,^,v^
•
THE LIBRARY
OF
THE UNIVERSITY
OF CALIFORNIA
PRESENTED BY
PROF. CHARLES A. KOFOID AND
MRS. PRUDENCE W. KOFOID
LESSONS ON SHELLS,
AS GIVEN TO CHILDREN
BETWEEN THE AGES OF EIGHT AND TEN,
IN A PESTALOZZIAN SCHOOL,
BY THE AUTHOR OF "LESSONS ON OBJECTS.
ILLUSTRATED BY TEN PLATES, DRAWN FROM NATURE.
SECOND EDITION.
PUBLISHED BY R. B. SEELEY AND W. BURNS! DE :
AND SOLD BY L. AND G. SEELEY,
FLEET STREET, LONDON.
MDCCCXXXVIII.
-H0S
o
6
PREFACE.
Quin ipsis doctoribus hoc esse curae velim, ut teneras adhuc
mentes more nutricum mollius alant, et satiari veluti quodam
jucundioris disciplinae lacte patiantur. Erit illud plenius interim
corpus, quod mox adulta setas adstringat. Hinc spes roboris.
QUINTILIAN.
' LESSONS on Shells ' may be considered as a
continuation of ' Lessons on Objects ; 9 the
principles of teaching illustrated in that little
work are here applied to an important and inter-
esting branch of Natural History. It is, like its
unpretending predecessor, a transcript of the
actual labours of the class-room ; and friends
who have visited the school, may retrace in the
printed work the process of which they were
witnesses. The end for which it is now laid
before the public is not that it may serve as an
instructive and entertaining volume to be placed
in the hands of children; this end is sufficiently
attained by several works of acknowledged
merit ; which, in order that the subject may be
more familiarly handled and more vividly con-
ceived, represent an imaginary group of pupils
vi PREFACE.
conversing and receiving instruction. The ob-
ject my sister has proposed to herself is to place
a volume in the Teacher's hands which shall
help him to re-act with his pupils the scenes that
are here described. It is not a drama offered for
perusal in the closet, but a manager's copy
commended to the conductors of other theatres
of education, to enable their liliputian corps
dramatiques to assume the same characters, play
the same parts, and I will not say, " fret their
little hour upon the stage," but enjoy the
genuine delight of intellectual activity judi-
ciously directed.
A want of order and arrangement in the early
part of ' Lessons on Objects/ has been alleged as
a blemish in that work ; but, in point of fact, its
miscellaneous character was a studied feature,
as better suited to the intellectual state of the
pupils. Their first step should be the exami-
nation of objects as nature presents them, or
rather as they see them in nature, that is, either
as insulated or as associated only by accidental
connection. When ideas are formed and correct
expressions familiarized, the business of classifi-
cation commences, the lessons assume a more
scientific character, and the pupils are prepared
to enter on the province of Natural History.
The training, then, which ' Lessons on Objects'
will have supplied for commencing ' Lessons
PREFACE. vii
on Shells,' will consist principally in the im-
proved faculty of observing natural features, in
the possession and command of a small voca-
bulary of scientific terms, in the habit of
classification, and in tlie practice of giving a
written summary of the knowledge acquired.
Several circumstances concur to recommend
conchology as the first branch of Natural
History to be studied by younger pupils.
Shells are of themselves interesting, from the
peculiarity of their forms and the variety of
their colours ; their characteristics are simple
and present themselves readily to the eye, and
a variety of interesting information may be given
respecting the animals which inhabit them.
Added to this the greater part of the specimens
may be procured at little expence, may be
easily preserved, and therefore continually re-
produced to the class, and besides may, without
fear of damage, be committed to the careless
hands of the youngest students.
It will however, I know, be objected by
staunch anti-reformers in education, that im-
prove the mode of teaching Natural History
as you will, you but teach better that, which
had better not be taught at all ; for that
whatever abridges the time given to classical
instruction, weakens the nerves and sinews of
the mind, and but debases the Corinthian
viii PREFACE.
column of ancient lore by introducing the
barbarous ornaments of modern science. My
answer is, we do not propose to devote a large
portion of time to Natural History in ordinary
cases, and even this will be taken principally
during those early years when very little real
progress is made in Greek or Latin. Every age
has its intellectual, as well as its moral claims ;
and though the stern discipline of early classical
instruction may offer some advantages, still the
hours devoted to the abstractions of grammar,
and the puzzling out ideas which have no pro-
totype in the child's mind through the dark
mist of a language little akin to his maternal
tongue, present very meagre food to that under-
standing they are supposed to strengthen. If
the child must lisp in Latin, let him do so ; let
his first Gradus ad Parnassum be through the
quagmires at its base ; the few choice spirits
that mount the summit may, perhaps, tread it
with firmer step, and enjoy the prospect with
keener relish ; but that step will riot be the less
firm, nor that relish the less keen, because a
daily hour was abstracted for ' Lessons on Ob-
jects,' or ' Lessons on Shells.' Not only are the
sciences so linked together that each gives each
a double charm, but the faculties of the mind
are so constituted, as that the vigour of each is
promoted by the due developement of the rest.
PREFACE. ix
And there is a harmony as truly existing in a
properly educated mind, as in a well- formed
and well-exercised body, though the harmony
of the former may not be so easily discerned as
that of the latter. ;•'
As years advance, the study of Natural His-
tory may be confined to those who manifest a
peculiar taste for it, or who exhibit little dispo-
sition for classical pursuits. For, as every age
has its intellectual claims, so also has every
grade of talent. The schools of the highest
reputation have generally been conducted too
exclusively to the advantage of the superior
class of minds. The fine porcelain has been
beautifully moulded and delicately pencilled,
but the coarser clay has been almost entirely
neglected. Yet many a young man who will
never shine in the Senate House or the Schools,
may yet pursue Natural History with success,
and find in such pursuits improvement for his
mind, a refuge from ennui, and a substitute for
sensual pleasures. There is much truth as well
as benevolence in a remark, I once heard from
an amiable coadjutor of Pestalozzi ; " Tout
terrain est bon si Ton sait le cultiver."
Much of the instruction thus communicated,
will doubtless fade from the mind ; but not with
it will pass away all the benefits arising from
these studies. In after years they may be recom-
x PREFACE.
menced with greater facility, in consequence of
the early training ; and every incidental reference
to these subjects, which conversation or litera-
ture may present, will be more readily seized,
and more clearly comprehended. And may it
not be anticipated, that through the judicious
introduction of these branches of education into
our schools, the latent powers of genius may be
kindled, and talents elicited that shall push
forward the limits of science,* and force the
Proteus nature to reveal still more of her secret
truths ?
C. MAYO.
Cheam, June 15, 1832.
* In confirmation of this idea it may be stated, that a very
ingenious improvement of the dissecting microscope, which has
merited a reward from the Society of Arts, has been invented
by a very young person brought up on these principles. I
have the more unmixed pleasure and honest pride in mention-
ing this fact, as it refers not to a pupil of my own, but to one
educated at Stanmore.
PREFACE TO THE SECOND EDITION.
IT has been objected to these Lessons, that
the children are instructed in the system of Lin-
naeus, one confessedly imperfect, instead of that
of Lamarck, which has been drawn out since the
science has been enriched by modern discoveries.
This objection would be most reasonable if the
chief aim proposed in the work had been to
teach the science of conchology, — but it is in
fact simply what its name imports, LESSONS ON
SHELLS ; having for its object, to develope
children's powers of observation, comparison,
and classification : and to cultivate habits and
tastes, which may in after life lead to a more
correct and scientific study of the subject. In-
tellectual power and not knowledge, being the
desideratum, that system should be pursued,
which the children can work out ; and there can
be no doubt that the Linnrean is the best adapted
for this purpose. The genera of Lamarck are
principally determined by the animal which the
children could not, with the exception of a very
xii PREFACE TO THE SECOND EDITION.
few instances, have the opportunity of examining
— indeed many of the shells composing his
genera are very rare, and they could only know
them by pictures ; the generic distinctions also
are often so minute that they would elude the
observations of minds unpractised in scientific
details. There is on the contrary something in
the simplicity and clearness with which the great
Swede seized and defined the broad outlines of
nature peculiarly suited to the capacities of the
young; and they may be led with very little
assistance, to group the shells according to his
arrangement, and to draw out from their own
observation the generic characters. Nor will an
acquaintance with the Linnsean system be with-
out its value, when they may desire to study a
more perfect classification than his; they will
find the task of subdividing, separating, and
arranging very much more easy than if they had
to work upon materials altogether new to them ;
— they will have points established in their minds
to which they may compare and attach the new
ideas presented ; their perceptions will be quick-
ened to discover similarities and differences ; and
they will find many of the difficulties that em-
barrass the student at the very threshold of
science, overcome by their previous lessons.
Some again have objected to the subject of the
lessons, as being so much less interesting than
PREFACE TO THE SECOND EDITION. xiii
that of plants or animals. This, however, is a
mistake; — the well-defined, and varied forms of
shells, their beautiful colours and markings,
render them particularly attractive, and afford
better opportunities than any other branch of
natural history, for calling into action the per-
ceptive powers. They are well suited to succeed
" Lessons on Objects ; " — the specimens may
be examined in the same manner, and their parts
and qualities described, and no other science
present the same facilities of bringing before
children, and exercising them in, the principles of
classification. An additional interest is given
to the study, when the accordance of the shell
with the habits of its animal can be traced.
In drawing out ' Lessons on Shells,' the fol-
lowing works have been consulted, and extracts
made from them.
Burrows' Elements of Conchology..
Turton's Conchological Dictionary.
Turton's Bivalve Shells of the British Isles.
Mawe's Conchology.
Montagu's Testacea Britannica.
Flemming's Philosophy of Zoology.
Lamark's Historic Naturelle des animaux sans
Vertebres.
The Conchologist's Companion.
Shaw's Nature displayed.
Sowerby's Genera of Recent and Fossil Shells.
Dillwyn's Descriptive Catalogue of Recent Shells,
The plates which illustrate this work, have
been drawn from specimens actually presented
to the class ; they are intended as an assistant to
the teacher, but not as a substitute for the shells
themselves in the instruction of pupils.
LESSONS ON SHELLS.
LESSON I.
ON THE MOLLUSCA.
Teacher. Do you know what these things
are which I have brought in as the subject of
our lesson to-day ?
Child. They are shells.
Teacher. Describe to me what you mean by
a shell.
Child. Oh, a shell is that which covers a
snail.
Teacher. Very true ; a snail has a shell, but
in saying this you do not explain to me the na-
ture of a shell. When you attempt to describe
anything, you should give such an account as
would instruct a person altogether ignorant on
the subject. Try again, and tell me what a
shell is.
Child. A shell is a hard covering or house
belonging to animals resembling slugs.
B
2 LESSON I.
Teacher. Of what use do you suppose shells
to be?
Child. They must be a defence and protec-
tion to the animals which they cover.
Teacher. Yes : shells are the hard coverings
of certain animals called mollusca, or mollusks ;
a name derived from mol Us, soft ; and esca,flesh ;
if you call to mind the animals enclosed in these
cases, you will not fail to observe how appli-
cable this term is to them. Give me some exam-
ple to prove that this name is well chosen.
Child. The snail has a very soft fleshy body.
Teacher. Yes, arid the mollusks in this res-
pect are all alike. I have brought you some to
examine; look at them well, and try and dis-
cover the characteristics which distinguish them
from other animals. Here are a snail, an oys-
ter, a muscle, and a slug.
Child. We shall not be able to say much
about such animals as these, they are so shape-
less and uninteresting in their appearance.
Teacher. Do not form so hasty a judgment.
T hope soon to convince you that it is your igno-
rance alone which causes you to view them with
indifference. There is not any part of the
creation which you can study, that will not
repay you for your labour ; and when you be-
come better acquainted with the different king-
doms of nature, you will experience an increased
pleasure in your walks; and objects that you have
hitherto passed heedlessly by, will rivet your
attention by the wonders they unfold to you ;
MOLLUSCA. 3
above all, my desire is that you should be led to
trace in all that nature presents, the hand of an
Almighty and beneficent Creator. When you
are struck with the organization of a plant, fitting
it for some particular purpose, or see the means
of defence possessed by one animal, of attack by
another, should your admiration rest in these
instruments, whilst you forget Him who prepared
and fitted the instrument for its appointed work ?
Suppose that you have yourself made or done
anything very nicely and with great pains for a
friend, would you feel satisfied, or think it just,
if, whilst your performance was admired, you
were forgotten ?
Child. I should consider such conduct very
unjust.
Teacher. And what lesson do you suppose
that I wish to teach you by drawing your atten-
tion to your own feelings when your industry
and ingenuity have been thus overlooked ?
Child. That when we are strnck with the
beauty and utility of any of God's works, we
should praise him for his wisdom, and thank him
for his goodness.
Teacher. It is with such feelings that I wish
you to study Natural History, and it would then
prove a very delightful and profitable employ-
ment.* You must now return to the consider-
ation of the animals before you. Examine them
* It is most important in giving instruction in Natural
History, early to accustom children to recognise the God of
nature in his works. If God be robbed of his glory, how
B 2
4 LESSON I.
carefully— exercise your different senses upon
them — mark the various parts of their bodies —
consider to what use each part is likely to be
destined — and reflect upon what you know of
their habits. By using well your senses and your
judgment, you will be able to find out much for
yourselves. When you are at the sea-side, or
out at sea, you may collect facts illustrative of
the history of these animals.
Child. That would be exceedingly interesting,
Teacher. Yes it would ; but you need not
wait for such "opportunities. Rivers, and even
the garden, will afford you specimens for obser-
vation : but what have you now to do ?
Child. To examine the animals before us, to
use our senses upon them as we did in our lessons
on objects, to name their parts, and the uses of
their parts as far as we know them.
Teacher. Yes. I wish you first to observe
these creatures attentively ; and that you may
discover readily what is peculiar to them, you
must in your own minds compare their qualities,
can we anticipate a blessing on our labours ? Has not expe-
rience proved, that the study of the wonders of creative
wisdom does not lead the natural heart to the Creator ? Is
it not notorious, that amongst the followers of science is con-
tinually seen the practical, if not the avowed Atheist. Let
this be a beacon to the Christian instructor, and let it be his
careful endeavour to guard against the fatal error of speaking
of God's works independently of him. As we are called upon
to walk by faith, and not by sight, it is essential to lead chil-
dren to see God in all things, and to trace Him who is him-
self invisible in those outward manifestations of his power and
goodness, which are within the reach of their observation.
MOLLUSCA. 5
parts and habits, with what you know of other
animals. First, tell me some qualities that appear
to you to be common to all the mollusca.
Child. Their bodies are soft, fleshy, moist,
and cold.
Teacher. Yes, you remember their name is
given to them from their softness. Observe
also the action of a snail when you come
near to it.
Child. It draws its body into its shell for
protection.
Teacher. Yes. The bodies of the Mollusca
are contractile, that is, have a strong power of con-
traction which they exercise by means of muscles.
What more do you remark in these creatures ?
Child. They have a thick skin which appears
loose in some of them.
Teacher. This skin is called the sac or man-
tle ; and is peculiar to the molluscous tribe. It
is constantly moistened by aslimy exudation, and
is also full of pores and glands, of which I shall
have occasion to speak in a future lesson. What
are pores ?
Child. Pores are very small holes.
Teacher. What do you know about glands ?
Child. I do not exactly know what glands
are ; but we have glands in our throats, are
those of the mollusks the same as ours ?
Teacher. They are of the same nature, but
much smaller than those in our throats. The
office of glands is to secrete or separate fluids of
various kinds from the general fluid of the sub-
6 LESSON I.
stance. Animals as well as vegetables, are
supplied with a greater number of glands ; the
tears of animals are an example of secretion
formed by means of such organs, so is the honey
of plants. As the glands form little reservoirs,
they often appear like small swellings, percep-
tible to the sight and touch. Now can you tell
me what glands are ?
Child. They are organs by which are secre-
ted some particular fluid from the general fluid
of the body.
Teacher. To return to the mantle ; it some-
times envelops the mollusk like a purse, leaving
an opening only where its mouth is situated ;
sometimes it extends on the two sides, forming
expansions which perform the part of fins.
Sometimes it spreads over the shell itself, which
in this case has always a fine polish. Compare,
as I desired you, the mollusk s, with other
animals, and tell me what further peculiarity
you discover in them.
Child. They have no bones, their bodies are
only a mass of soft flesh.
Teacher. They have certainly no bones ; but
in the mollusks which we purpose studying,
the shell, by acting as a support to the body,
seems in some measure to answer the purpose of
bones. What more do any of you discover
in these animals ?
Child. They do not appear to have any blood .
Teacher. They have not red blood as we
have ; but are they composed entirely of solid
matter ?
MOLLUSCA. 7
Child. No, for when a snail is trodden upon,
a white fluid issues from it ; is this its blood ?
Teacher. Yes, it may be considered as a kind
of blood. How does it differ from that which
circulates through our bodies ?
Child. It is white and cold.
Teacher. True ; and in consequence some
naturalists have not considered it as blood, and
have described the mollusca to be exsanguin-
eous ; a term signifying without blood, and
derived from Latin ex9 out of, and sanguine,
blood. As this fluid flows through their bodie.s
in vessels issuing from their hearts, it is now
generally called their blood. What are you
watching in the snail ?
Child. The very quick manner in which it
draws in its horns, and shrinks into its shell, if
it is touched.
Teacher. What would you determine with
respect to the animal from this circumstance ?
Child. That it has the sense of feeling.
Teacher. Yes ; and which part appears most
sensitive ?
Child. The horns.
Teacher. And do you observe how the little
animal feels about, and tries with these projec-
tions which you call horns ? They have from
thence been termed Tentacula9 from the Latin,
tentare, to try or feel. How many tentacula have
snails ?
Child. Four.
Teacher. The tentacuia vary in number ;
8 LESSON I.
many mollusks have only two. The sense of
feeling resides in the nerves.
Child. Oh ! then the mollusks must have
nerves.
Teacher. Yes, they have nerves. Do you
perceive any other organs of the senses besides
the tentacula?
Child. There are black specks on the horns
of the snail which appear like eyes.
Teacher. These specks are the organs of
sight, of which mollusks have never more than
one pair. The sense of seeing, however, is not
universally possessed by this class of animals.
The organs of hearing and smelling have never
been discovered in any of them, but they are sup-
posed to possess the latter from the readiness
with which they select suitable food. This cir-
cumstance also proves that they possess the sense
of taste. You must now recapitulate all that has
been said concerning the mollusca. Whence is
the name derived ?
Child. From mollis, the Latin for soft.
Teacher. What kind of body have they ?
Child. Cold, slimy, soft, and fleshy.
Teacher. Yes ; and another quality you
observed when I touched the snail several
times.
Child. That its body is contractile.
Teacher. And what enabled it so quickly to
contract its body, and retreat into its shelter ?
Child. Its being furnished with muscles.
Teacher. When you compare these animals
MOLLUSCA. 9
with others, in what respect do they appear
deficient ?
Child. They have no bones, the shell acting
as a support to their bodies, which are attached
to it by muscles.
Teacher. What envelops the mollusca ?
Child. A sac or mantle.
Teacher. Describe the mantle.
Child. The mantle is full of pores and glands
and is moistened by a slimy exudation— some-
times it quite encloses the animal, having only
one opening like a purse, sometimes it has ex-
pansions at the sides, like fins, and sometimes it
spreads over the shell.
Teacher. What are glands ?
Child. Small lumps containing fluids, which
are separated from the blood.
Teacher. Yes, in animals the glands secrete
fluids from the blood ; but in vegetables from
the sap. Have these animals any blood ?
Child. Yes ; but it is white and cold.
Teacher. In what respects is it similar to blood ?
Child. It circulates through the body in
vessels issuing from the heart.
Teacher. What senses are enjoyed by the
mollusca ?
Child. The senses of feeling, seeing, tasting,
and, it is supposed smelling.
Teacher. In what part of their frames is the
sense of feeling most acute ?
Child. In the tentacula.
Teacher. Tell me the derivation of that term ?
10 LESSON I.
Child. It is derived from the Latin, Tentare,
to try.
Teacher. But what must they possess in
order to be able to feel ?
Child. Nerves.
Teacher. I will now read to you a summary
of your lesson, and I shall expect you afterwards
to write it from recollection.
Teacher. The mollsuca have soft, slimy, cold,
fleshy, and contractile bodies. They have
no bones, but their shell acts as a support to
their frame. They have muscles by which
they are attached to their shells, and by which
they move their bodies. They are enclosed in a
skin called the mantle, or sac, which is full of
pores and glands. Sometimes the animal is so
completely enveloped in this, as only to present
an opening where the mouth is situated, some-
times it spreads over the shell, and sometimes it
has external expansions answering the purpose
of fins. The mollusca have not warm red blood,
but a white cold fluid issues from their hearts
and circulates through their frames. They
have nerves, and consequently, feeling ; and this
sense seems most accute in their tentacula. Some
have eyes, but others do not enjoy the sense of
sight. They appear to have the power of smel-
ling and tasting, but no traces of ears have been
discovered.*
* This little summary of the substance of the lesson may
be read over twice to the children, and they should then be
MOLLUSCA. 11
LESSON II.
( To commence with a repetition of the summary of the former
lesson.)
Teacher. Examine these animals again, com-
pare them with insects, and tell me if you
observe any deficiency in their construction.
Child. They have not any limbs.
Teacher. Very true. They have not limbs
or joints, as insects, nor are they divided, or
moved by means of rings, as worms.
Child. Yet they move about.
Teacher. Yes ; the greater number of
mollusks have the power of locomotion, that is,
of moving from place to place ; the term is de-
rived from the Latin locus, a place. We will
required to write it as well as they can from recollection. It
would be desirable also that they should repeat it at the com-
mencement of the succeeding lesson. This process may appear
tedious, but the result will be most satisfactory both to the
teacher and pupils. The latter should acquire so clear a know-
ledge of the facts brought before them, and have them so well
imprinted on their minds, that they may, through all their
progress, be enabled without confusion or hesitation, to recur
to each preceding step. Their information should be like a
chain, which is held unbroken in the grasp ; and when this is
accomplished, a power of mind is elicited which,, independently
of the knowledge obtained, will prove most valuable when
applied to more important subjects.
12 LESSON II.
first examine the organs by means of which this
power is exercised. In what manner do snails
and slugs make their way along the ground ?
Child. Their skin expands at the sides of the
body, and adheres to the earth, and then they
draw themselves on.
Teacher. This fleshy expansion under their
bodies is full of muscles, which they dilate and
contract at pleasure. It adheres like a sucker,
and the animal advances by fixing the fore part
to the ground and drawing the remainder after
it. This instrument is called a foot. In some
species, as the snail, it is attached to the under
part of the body by its whole length, but in
others it is free at one end, and can be extended
or drawn in at pleasure. When it is free it is
called a leg, and is generally tongue-shaped ; it
is frequently used as an organ of motion, but
sometimes the animal employs it as a paw for
digging holes in the sand or mud. But do you
think that this organ will enable the mollusks to
advance in all the situations in which they are
placed ?
Child. No, not when they are in the water ;
then they must swim.
Teacher. Yes, and this action is performed
either by the serpentine movements of the foot
and body, or by the movement of expanded
portions of the skin or tentacula, which forces
them onwards in the same manner as oars pro-
pel a boat.
Child. Have all the mollusks that live in
MOLLUSCA. 13
the water either tentacula or expansions of the
skin?
Teacher. No ; some have no such elongated
parts. I think you might have discovered this
yourselves by observing one of the animals
before you.
Child. Oh yes, the oyster. Such mollusks
cannot move then.
Teacher. That is not true of all, some are
immoveably attached to the spot where they
first received life ; but others have the power of
leaping or shifting their positions with a sudden
jerk, produced by rapidly shutting the two
pieces of their shells ; others again transport
themselves from one spot to another by the force
with which they draw in and eject the fluid in
which they live. Many species are furnished
with a kind of bladder by inflating or contract-
ing which they can rise or sink in the water as
circumstances require. Try and enumerate the
various means of locomotion possessed by the
mollusca.
Child. Many creep by means of a fleshy
elongation, which is in some a foot, in others a
leg. In the water they swim, making their way
either by the serpentine movement of their
bodies, or by the use of tentacula. Some can
rise and sink in the sea, and some make a leap
by rapidly closing their shells, or by drawing in
water and suddenly forcing it out again.
Teacher. When we study the different kinds
of mollusca, I shall speak to you more fully of
14 LESSON IL
their peculiar habits. Did you ever observe
when you have been on the sea-coast, numerous
shells clustered together on the rocks and stones ?
Child. Yes, barnacles ; are they the animals
which never move from the spot to which they
are attached ?
Teacher. Yes, the barnacles and many other
mollusks live and die on the spot where their
existence first commenced.
Child. How are they fixed to the spot ?
Teacher. Some of them, as the barnacles,
are cemented to the rocks by the same sub-
stance of which their shells are formed ; others
have a less permanent mode of adhesion, and
fasten themselves by means of a viscid liquid
which they discharge from glands in their bodies ;
some produce silky filaments, one extremity of
which remains in connexion with themselves,
while the other is fixed to marine substances,
and thus anchoring themselves, they float secure
in the ocean. The bundle of filaments which
the animal draws from his body for this purpose
is called a byssus.* Do you know any other
shells that are with difficulty removed from the
rocks ?
Child. Yes, the limpet.
Teacher. The manner in which this mollusk
* The children should see and examine for themselves these
contrivances. A pinna with its byssus, and barnacles on a
stone are easily procured. The web of the spider would give
them a good idea of the work of the pinna, being produced in
a very similar manner.
MOLLUSCA. 15
fixes itself upon the rocks, is very simple,
though very curious. It forms within its
shell, a vacuum, that is, a space free from air,
derived from Latin, vacuws, empty. By filling up
the hollow of the shell with the fleshy substance
of its body, it expels the air, and having fastened
its body to the rock by a viscid substance, con-
tracts itself in the centre, thus leaving a space
within the shell entirely free from air. As there
then is no internal expansion of this fluid,
the pressure of the external atmosphere meets
with no resistance, and in consequence acts with
so much force upon the shell, that it cannot be
removed from its situation without great effort.
Repeat to me now the different means of attach-
ment used by the mollusca.
Child. Some fix themselves by silky fila-
ments called a byssus, some by a viscid cement,
others by forming a vacuum, and others attach
themselves to the rocks by the same substance
of which their shells are made.
Teacher. The shells which by any of these
means are rendered stationary, are called fixed
shells, the others free shells. Does anything
strike you with regard to these two kinds of
mollusca ?
Child. The inhabitants of the fixed shells
must be badly off. They cannot procure nour-
ishment.
Teacher. They cannot indeed go in search
of it, but the continued motion of the waves, or
the flowing of the tide brings a fresh supply of
16 LESSON II.
water swarming with the little animals upon
which they subsist, and some increase the rapi-
dity of this supply, by forming currents in the sea.
Child. What very clever contrivers these
animals seem to be.
Teacher. Yes, and your remark leads me to
an important consideration, to which I wish to
direct your attention. How do these little ani-
mals know that it is well for them to attach
themselves to other substances. How have they
learnt to form the vacuum, or weave the silken
filaments ?
Child. Is it riot instinct that directs them 1
Teacher. Yes, but can you tell me what
instinct is ?
Child. It is something that guides animals.
Teacher. Is man taught in the same way ?
Child. No, we have reason, and can think
about what we do.
Teacher. Well, let us consider a little the
difference between that which directs man, and
that which guides other animals. Suppose a
child were to see a fire for the first time : not
knowing its nature, he might perhaps put his
finger into it. Would he do so, do you think,
a second time ?
Child. No, he would recollect the conse-
quences of having done so before.
Teacher He would have learnt then from his
own experience : but is all knowledge obtained
by our own experience ; do you not know any
thing but what you have discovered yourself ?
MOLLUSCA. 17
Child, We learn from the accounts of others.
Teacher. True, we are instructed by the
experience of others. But watch any animal, a
bee for instance : when it makes its cell, does
it try several times before he succeeds ?
Child. No, he does it perfectly at the first
attempt.
Teacher. Has it been taught by its own
species ?
Child. No.
Teacher. What then is the difference between
the principle that guides the bee, and that which
guides man ?
Child. Man is taught both by his own ex-
perience, and that of others ; but the bee acts
rightly without either.
Teacher. Yes ; it is directed immediately
by a principle implanted in it by the Creator.
This principle is called instinct, and is well
defined to be prior to experience, and indepen-
dant of instruction. I will now read to you the
summary of to-day's lesson — attend, that you
may be able to write an account of it from
recollection.
Many of the mollusca, though destitute of
jointed limbs, have organs of motion ; some
have a fleshy expansion extending the length of
the body, called a foot ; this is full of muscles,
by which it is moved, it acts like a sucker, and
the animal advances by fixing the fore part to
18 LESSON II.
the ground, and drawing the remainder after it.
This organ is sometimes free, and can be ex-
tended or contracted at pleasure ; it is then
called a leg, and is used either as an organ of
motion, or as a paw for digging holes in the
sand or mud. In the water, some mollusca
advance by means of the serpentine motion
of their bodies, others by the movement of either
expanded portion of the skin or tentacula.
Some, quite destitute of any separate organs of
motion, effect a change in their position by
ingenious contrivances ; thus, the common scal-
lops, by rapidly shutting the two pieces of
their shell, can transport themselves a short
distance ; and others send themselves forward
by drawing in water and ejecting it again with
great force. Many species are furnished with a
kind of air bladder, by inflating or contracting
which, they rise and sink in the water as cir-
cumstances may require. Some, however, have
no power at all of moving, but remain fixed
through life to the spot where they commenced
their existence. Their modes of attachment
vary ; some firmly fix themselves by the same
materials of which they make their shells :
others glue themselves by a viscid cement drawn
from glands in their bodies ; and, others throw
out a byssus, and anchor themselves securely to
some rock. The limpet, by forming a vacuum
in his shell maintains a firm hold of marine sub-
stances. The shells thus rendered stationary,
are called fixed shells, whilst those inhabited by
animals that move about, are termed free shells.
MOLLUSCA. 19
LESSON III.
Teacher. What organs in the mollusca have
we considered ?
Child. The organs of sense and of motion.
Teacher, And what other organs are essential
to animal existence ?
Child. All animals must have organs by
which they feed themselves.
Teacher. Have you ever observed snails
eating ?
Child. Yes ; I have seen them devour a leaf,
and I should think they must have teeth.
Teacher. They have two jaws which are fur-
nished with small teeth, fitted for cutting vege-
table substances.
Child. Have all the mollusca mouths like
that of the snail ?
Teacher. No, the mouths of the different
species, as well as their other organs, are adapted
to the peculiar wants and habits of the animals.
Some have only a simple opening to receive the
little animalcula brought to them by the waves,
and which do not require mastication.* Most of
those which live upon the produce of the vege-
table kingdom have a muzzle with jaws which
are either horny or armed with teeth, f The
* The Oyster. t The snail.
C 2
20 LESSON III.
carnivorous * mollusca have usually a kind of
proboscis ; this instrument is a fleshy pliable tube
terminated by a round aperture, with a cartilagi-
nous edge armed with little teeth. f The proboscis
is supplied with muscles, by means of which
the animal can protrude or draw it in at pleasure;
many use it to pierce other shells, that they may
suck out the flesh of the inhabitant. I have
mentioned to you three different kinds of mouths
which mollusks are found to possess ; describe
them to me.
Child. Some have only a simple opening,
others have jaws, either of a horny substance,
or armed with teeth ; and others possess a plia-
ble fleshy proboscis, moved by muscles, and ter-
minated by a cartilaginous ring which has teeth.
Teacher. Which are the feeders upon vege-
tables, and which upon animals,?
Child. The mollusks which have a muzzle
feed upon vegetables, those with a proboscis are
carnivorous.
Teacher. In feeding there is another point to
be considered, how the food is to be brought to
the mouth. How do we manage this operation ?
Child. By means of our hands ?
Teacher. And what makes it particularly
needful that man should possess hands ?
Child. His erect position.
Teacher. You have often had an opportunity
of watching some of the mollusks which are
* From the Latin carne, flesh, and voro, I eat.
t Voluta tnusica.
MOLLUSCA. 21
vegetable feeders, you can tell me how they
manage.
Child. The snail feeds upon vegetables, it
crawls upon its fleshy foot till it reaches a plant,
and then gnaws it with its jaws.
Teacher. The animal feeders stretch out
their proboscis and catch hold of their prey, and
some grasp it with their tentacula, and thus
bring it within reach of their mouths. Those
mollusks which have only an opening, have a
supply of food brought to them by the continued
movement of the waves and the flowing of the
tides, and you must remember my telling you
of some who ingeniously increase this supply by
creating an eddy in the water. I have brought
you an oyster and a snail, and wish you to com-
pare them together, and tell me what appears to
you to be the most striking difference between
the two.
Child. The snail has a head, but the oyster
is only as oft lump of flesh, and has no appear-
ance of a head.
Teacher. Many of the mollusks like the
oyster, have no obviously distinct head. This
circumstance has led naturalists to divide these
animals into two great classes. How should
you think they are distinguished ?
Child. One class contains those mollusks
which have heads ; the other, those which are
destitute of heads.
Teacher. The former are called mollusca
cephala from the Greek /ce^aX»j (kephale) a head;
the latter, mollusca acephala from the Greek
22 LESSON III.
a without, and K€<paXy a head. The mollusca
acephala have not a distinct head, nor any ap-
pearance of the organs of sight or hearing, their
mouth is only a simple opening, and their organi-
zation altogether is much more simple than that
of the mollusca cephala. They are aquatic ani-
mals, and their shell is composed of two pieces, to
which they are attached by muscles. Which of
these mollusks would you place in this class ?
Child. The oyster, the scollop, and the
muscle.
Teacher. Here is the summary of to-day's
lesson; — read it carefully, and then take pains
to write me a correct account of it.
The organs of nutrition possessed by the
mollusca, vary according to their habits. Those
which feed on vegetables, have a muzzle com-
posed of horny jaws sometimes armed with
teeth. Many of the carnivorous mollusca, have
a fleshy, pliable proboscis, moved by muscles,
and terminated by a cartilaginous border, fur-
nished with teeth ; others have only a simple
opening, and possess no organ of mastication.
The mollusca are divided into two great classes ;
one contains those animals possessing a head,
which are called mollusca cephala, the other
contains those which are destitute of a head,
and are called mollusca acephala. The latter
are distinguished by a much more simple organi-
zation, live invariably in water, and inhabit
shells composed of two pieces.
MOLLUSCA. 23
LESSON IV.
(Before proceeding to the study of Shells, there should be a
recapitulation of all the children have learnt concerning the
animals, and a summary read to them and written down by
MOLLUSCA.
The mollusks have a soft, cold, slimy, and con-
tractile body moved by muscles. They have no
articulated moveable parts as limbs ; in some,
the organs of motion are tentacula of different
forms ; in others, a fleshy foot extending along
the underpart of their bodies ; this fleshy sub-
stance is sometimes free and pliable, and can be
projected and drawn in at pleasure. The bodies
of the mollusks are enveloped in a sac or mantle
of skin full of pores and glands, which some-
times spreads over their shell. They are desti-
tute of bones. They have not red warm blood,
but a white cold fluid circulates through their
frames in vessels issuing from a heart. They
have nerves connected with their different organs.
They are divided into two classes. The first,
mollusca cephala, have a distinct head, bearing
lips or jaws, and are furnished with eyes and
tentacula. The second, mollusca acephala, have
a more simple organization ; they have no dis-
tinct head, and are destitute of jaws and other
hard parts of a mouth ; they inhabit shells
formed of two pieces.
24
LESSON V,
SHELLS.
Teacher. Well, did you find the study of
the mollusca as uninteresting and unprofitable
as you expected it to be ?
Child. Oh no, we have, on the contrary,
learnt much that has interested and surprised us.
Teacher. And what useful lesson may you
apply to yourselves from the mistake you first
made ?
Child. Not to look upon any of the works
of God with indifference or contempt, but to
feel convinced that if they fail to excite our
admiration, it is on account of our ignorance.
Teacher. The more you study Natural His-
tory, the more you will be inclined to acknow-
ledge this truth. Now I wish you to examine
the coverings of the mollusks, — are there any
parts of other animals that can be compared to
shells ?
Child. The hard coverings of beetles are
something like them.
Teacher. What strikes you as being the
principal difference between shells and the case
in which some insects are enclosed ?
Child. Shells are like houses ; but the cover-
ings of insects fit the different members of their
SHELLS. 25
bodies like a skin, and seem to be a part of the
animal itself.
Teacher. The coverings of insects are united
to their different members ; but shells are at-
tached to the mollusks only in one or two places
by muscles. You must have had the opportunity
of observing how they adhere in one spot to their
shell.
Child. Yes, you are obliged to cut the
oyster away from the shell.
Teacher. Besides the difference which you
have observed in the covering of insects and
mollusks, their composition is not the same.
You remember learning in your lessons on lime,*
the animal substances of which it forms a prin-
cipal part.
Child. Yes, our bones consist principally of
carbonate of lime, and I think you said that
shells were also a calcareous substance.
Teacher. Shells are composed of carbonate
of lime, with the addition of a small portion
of an animal substance called gelatine : the
covering of insects is a phosphate of lime. The
substance of shells is testaceous, having the
hardness of baked earthenware, in latin, test a ;
and hence the mollusca enclosed in them are
called testaceous mollusca : the covering of in-
sects is crustaceous, having the hardness of crust,
in latin, crust a.
Child. But whence is the carbonate of lime,
* See Lessons on Objects, page 173, Sixth Edition.
26 LESSON V.
of which shells are composed obtained ? Is it
found in the sea ?
Teacher. It exudes from the skin of the
animal, which as I told you, is furnished with
numerous glands. In these is secreted the cal-
careous matter.
Child. How very wonderful that they should
thus be provided with materials to make their
abode ; but how is the shell formed from this
substance ?
Teacher. The little animal you formerly
despised is its own architect, and constructs a
dwelling exactly suited to its wants. One of our
divines who has written a volume to prove that
the works of creation are alone a sufficient evi-
dence of the existence of a wise and beneficent
God, says, speaking of a shell, " I do not
know whether weight being given, art can pro-
duce so strong a case as some shells."* What
do you now think of the workmanship of these
little creatures?
Child. It is very wonderful, and how re-
markable that there should be such a variety of
shapes in shells !
Teacher. The shape of the shell is deter-
mined by that of the animal itself.
Child. But the mollusk does not always
continue the same size.
Teacher. Very true. It is quite minute
when it comes out of the egg, and the shell is
* Paley's Natural Theology.
SHELLS. 27
then proportionably small ; but as the animal
increases in size, it adds to the dimensions of
its shells by additions made at the opening, and
to its thickness by a succession of layers de-
posited within.
Child. Do the mollusks always construct
their shells of the proper shape ?
Teacher. Yes, the carpenter with his rule
and compass is not so exact and unerring as
these heaven-taught builders. But is form the
only point that attracts your attention in these
shells ?
Child. Oh no ; they have most beautiful
colours and markings ; these cannot belong to
the. carbonate of lime.
Teacher. No, and again I shall excite your
admiration of the little animal, when I tell you
that he not only constructs, but also adorns his
habitation.
Child. But whence can he procure such
beautiful colours ?
Teacher. He is furnished in himself with all
that is necessary both for the constructing and
beautifying his shell ; his skin you remember is
full of pores ; these contain colouring fluids,
which, penetrating the calcareous substance
before it is hardened, form its diversified tints.
Child. It seems very wonderful that so
many shells should have the same pattern.
Teacher. It is indeed most wonderful. I can
tell you however how it is supposed to be effected .
The pores containing the colouring matter are
28 LESSON V.
arranged in the skin of the mollusks with the
same undeviating regularity as the spots upon
the leopard, or the stripes upon the tiger, and
when the liquid exudes^ it stains the shell, and
the uniformity of the pattern is the consequence
of the order in which the pores are placed in the
mantle. Now look at all these shells, and con-
sider them only in reference to their colours and
markings.
Child. The colours in some are very beauti-
ful, and there is great variety of patterns.
Teacher. This is very true ; but are they
all different ?
Child. No, there are some that have quite
the same pattern.
Teacher. Then you may observe two points
especially with regard to the markings ; what
are they ?
Child. That there is a very great variety,
and yet some are alike.
Teacher. Do you suppose that their being
alike is accidental ?
Child. Oh no, it could not have arisen from
chance.
Teacher. Very true, nor can we fail to ob-
serve, that however great the variety may be in
individual specimens, all the works of creation
present a beautiful principle of order and uni-
formity. Prove if you quite understand what
I mean, by applying it to these shells.
Child. There is a very great variety of pat-
SHELLS. 29
terns and shapes, and yet they are all alike in
many respects.
Teacher. They have undoubtedly all a
general resemblance, which enables you at once
to determine that they are shells ; but more than
this, do you not observe that some are more
alike than others ?
Child. There are some that are very much
alike in shape.
Teacher. Yes, and yet differ in other res-
pects ; but is this all that you observe ?
Child. No, there are some that appear ex-
actly alike.
Teacher. Thus when you look at a collection
of shells for the first time, you are struck by
their general similarity, and you at once call
them all shells. After a little inspection, it
will be evident that amongst them, some have a
few points qf resemblance, and that others are
quite alike in all respects. Thus you begin to
perceive that the variety which at first almost
bewildered you, is limited by a principle, and
whilst your eye is gratified by the diversity,
your judgment is satisfied by the order you find
preserved. Tell me a similar circumstance in
another class of natural objects.
Child. Flowers afford one. All roses are
alike in general appearance, but the Moss Rose
is easily distinguished from the China Rose.
Teacher. The variety exhibited in the works
of nature cannot fail* to delight us, and the re-
semblances observable in them enable us to
30 LESSON V.
classify and arrange them. There is still one
point with respect to shells which we have not
considered ; I mean the situations which they
occupy. Where are shells found?
Child. Most of them in the sea, but some on
land, and others in ponds and rivers.
Teacher. Those which live on land, are
called terrestrial, from the Latin, terra, earth.
These mollusks feed on vegetables, and have al-
ways four tentacula, and their eyes are placed
at the tips of these organs. The shells which
are found in fresh water, are called fluviatile,
from the Latin fluviws, a river; they are gene-
rally of a corneous colour, and are semitrans-
parent ; their mollusks have only two tentacu-
la, which are flat, having eyes at the base.
The shells inhabiting the sea are termed marine,
from the Latin, mar e, the sea ; they are much
the most numerous, the most beautiful, and the
most highly prized. I will now recapitulate to
you the substance of the lesson of to-day, and
you must write it on your slates.*
Shells resemble the hard coverings of insects;
the principal difference between them is, that
the former are only attached to the animal in
one or two places, while the hard case of insects
* It would be desirable before the recapitulation, that the
teacher should question the pupils upon the points that have
been discussed, as in a preceding lesson.
SHELLS. 31
fits the members of their bodies, and has more
of the nature of a skin. The substance also
differs ; that of shells is a carbonate of lime, with
a small portion of an animal substance called
gelatine, and is termed testaceous ; the case of
insects is a phosphate of lime, and is called
crustaceans. The carbonate of lime, of which
the shells are formed, is secreted in the glands
of the mantle, and oozing out, takes the form of
the animal, and gradually hardens. When the
mollusk is small, the shell is proportionably so ;
but as the animal increases, it adds to the dimen-
sions of its abode by additions at the opening,
and to its thickness by layers from within. The
colour and markings with which the shells are
diversified, are produced in the pores of the
mantle, and are there arranged in the same pat- ,
tern as that which appears on the shell. Shells
are either terrestrial, tiuviatiie, or marine.
LESSON VI.
Teacher. Let us now consider in what situa-
tions shells are placed. They are, as you know,
exposed to the dashing of the waves, borne by
the violence of storms against rocks ; and car-
ried down rapid rivers. You can readily imagine
32 LESSON VI.
the consequences of their being situated amidst
such perils.
Child. Yes. The shells must frequently be
broken, and the poor animals perish.
Teacher. Your first conclusion is true. The
shells are often broken or injured; but God
always makes a suitable provision for the cir-
cumstances under which he places his creatures.
Recollect that the same Almighty Being who
rules the tempests, directs also the movements
of the minutest animals, he knows every effect
of the former upon the latter, for he sees all the
workings of his mighty plan. I am sure that
you must know from scripture that such is
the case.
Child. Yes ; without Him not a sparrow
falleth to the ground.
Teacher. This providential care is very
evident in the history of mollusks. We find
that the construction of the shell varies accor-
ding to the situation in which it is placed.
Some shells found in the rapid rivers of
America,* are fitted by their great hardness and
thickness to contend with the most boisterous
elements;! others on the contrary, by their very
lightness, seem constructed to float on the sur-
face of the sea, and offering no resistance, are
carried along gently by its waves. Some of
the mollusks,t by adding to the weight of their
little bark, are enabled to descend and seek a
* The Unio. t Helix lanthina. % Nautilus.
SHELLS. 33
shelter in the deep of the ocean ; some * you
have learnt, anchor themselves to rocks and
thus bid defiance to dangers. But in spite of
all these, and many more equally beautiful con-
trivances, a breach is often effected in the habi-
tation of the mollusca.
Child. And then the poor animals must
perish ?
Teacher. This is by no means inevitably the
case, for they are gifted with the power of re-
pairing their shells.
Child. How can they manage this ?
Teacher. By a discharge of the same cal-
careous matter, of which they at first constructed
their shells. You might by your own expe-
rience prove this to be true ; if you procure
in the spring some common snails, break off
a part of their shells, then giving them a supply
of food, place them under a glass that you may
watch their operations. You would observe
first a frothy matter exuding from that part of
the animal which you had uncovered, and form-
ing a film ; in a short time a second discharge
would raise the first to the level of the external
surface of the shell, and by degrees fresh acces-
sions would give the new part the thickness and
substance of the old shell.
Child. It would be very amusing to watch
this experiment.
Teacher. But do you not admire the instinct
* Pinna.
D
34 LESSON VI.
that so wonderfully directs these little animals
in their self- preservation ?
Child. It is very surprising certainly, that
such a worm should have the power of remedying
so great disasters. But could not God have
enabled them to form their shell at first too
strong to be liable to imjuries, or else have
placed them out of the reach of danger ?
Teacher. Doubtless God could have done
either. But all creation, as it is now constituted,
reads us the lesson which we ought never to
forget, that the work which was pronounced
*' good," when it first came from the Almighty's
hand, has been marred, Every where we trace
the consequences of the fall — all nature in its
tendency to decay, shews the sentence of death
passed upon it, yet it bears even in its fallen
state, the impress of divine love and mercy.
Now examine again the shells before you, and
try and discover where any of them have been
repaired.
Child. Several appear patched.
Teacher. These patches mark where some
hole has been covered over.
Child. But here are some shells which have
regular seams,
Teacher. These seams indicate where the
animal, in consequence of its own growth made
an addition to its residence. Observe this shell.
(Bucinum flammium) Can you not trace the
gradual extension of the shell from a very small
size?
SHELLS. 35
Child. Yes, it is marked by a rib like that
at the opening.
Teacher. You will find a great many shells
which shew that they have been enlarged in the
same manner. The fresh layers are parallel to
the margin of this opening called the mouth,
and the meeting of the edges of the new and
old matter is often marked by a ridge more or
less elevated,
The shell of the adult animal is often armed
with inequalities on the surfaces, as spines or
tubercles, which do not appear in the young
shell. I will now give you a summary of the
lesson of to-day,
SUMMARY.
The mo 11 use a are often placed in situations
of great danger. They are exposed to the
dashing of the waves, often borne by th« vio-
lence of storms and cast against rocks or stones.
Some placed in rapid rivers are occasionally
hurried along by the impetuosity of the stream,
God, however, always makes a suitable provi-
sion for the circumstances under which he places
his creatures, and when he apportions to them
spots of danger, arms them with the means of
protection and defence. Thus we find that the
shell and the habits of the mollusca are adapted
to the situations which they occupy. Some that
belong to the rapid rivers of America have an
exceedingly hard and substantial shell, fitted to
contend with the most boisterous elements ;
D2
36 LESSON VI.
others, on the contrary, by their very lightness
are enabled to float on the surface of the water,
and offering no resistance, are gently carried
along by its waves ; some anchor themselves
securely by a byssus to rocks, and thus bid defi-
ance to danger ; others, by adding to the weight
of their bark can descend and seek a shelter in
the bed of the ocean. There are many other
beautiful contrivances for their preservation.
But in spite of these, a breach is sometimes
made in their shell ; but this they have the
power of repairing, by exuding a calcareous
matter, similar to that with which they at first
constructed the shell.
LESSON VII.
Teacher. To-day you shall tell me all that
you remember respecting shells, and I will put
it together in a more regular manner.
SHELLS.
Shells are the coverings or habitations of a
species of mollusca. They are formed by the
animal itself of carbonate of lime and gelatine :
these substances are secreted in glands in its body.
The colouring matter exudes from the pores
of the mantle, penetrates the shell before it is
hardened, and the colours being arranged in
SHELLS. 37
order in the mantle, produce the peculiar mark-
ings which belong to the different species.
When any accident happens to the shell, the
animal is enabled to repair it. The size of the
shell is in proportion to that of its inhabitant ;
small at first, but is increased from time to time,
till the animal has attained its full size.
Teacher. Before we enter more fully upon
the study of shells, and their classification, I
wish to direct your attention to two circum-
stances very conspicuous in the works of the
Creator. The first is, the economy displayed
by God ; * you seem surprised.
Child. Tfes, it is so very extraordinary to
talk of God beipg economical, when every thing
is at his disposal, and he can create at his
pleasure.
Teacher. Do you not recollect our Saviour
giving an example of economy at the very time
that he was manifesting his omnipotence ?
Child. Yes, after he had fed the multitude
with the two loaves and five small fishes, he
commanded that the fragments should be gathered
up, that nothing be lost.
Teacher. The same principle is displayed in
the works of creation. Nothing is superfluous
or without its use. The second principle to
which I wish you to give your attention is, The
compensatory providence of God.
* Paley's Natural Theology,
38 LESSON VII.
Child. What does that mean ?
Teacher. To compensate is to make amends
for any defect, or to give something of equal
value, for any thing taken away. In nature we
often find objects in which there appear numerous
deficiencies, but on further examination we dis-
cover that these are compensated or made up
by some admirable contrivance. To make this
clear to you, we will reflect upon a well-known
instance. Consider the spider. What is its food ?
Child. Flies and other insects.
Teacher. And what mode of pursuit should
you think best adapted to catching such
creatures ?
Child. Flying, but the spider has no wings.
Teacher. Here then appears a sad deficiency :
winged insects are the natural food of the spider,
and he has not the means of pursuing them.
Yet do you not perceive how God has compen-
sated this deficiency ?
Child. You mean by teaching him to con-
struct a web to entrap the flies.
Teacher. This instance will give you a good
idea of what is meant by the compensatory pro-
vidence of God. It is much displayed in the
singular fitness of shells for their respective
localities. Thus those which move easily from
place to place, and consequently are able to
elude their pursuers, are often adorned with
vivid colours, whilst those which are incapable
of locomotion, escape the notice of their ene-
mies by resembling in colour the stones and
SHELLS. 39
weeds which surround them. Now tell me the
two principles which are to be traced through-
out the works of the Creator.
Child. The economy of God and his com-
pensatory providence.
Teacher. Bear these principles in mind, and
you will see many illustrations of them in the
habits of the mollusca. The following lines of
Pope will help to fix them in your memories :
Nature to these, without profusion^ kind,
To proper organs, proper powers assigned ;
' Each seeming want' compensated of course,
Here with degrees of swiftness, there of force.
LESSON VIII.
•• Teacher. What do you think will be our
next step in the study of shells ?
Child. To learn the names of shells, and how
to class them.
Teacher. What do you suppose first led
people to adopt classification ?
Child. The wish to arrange their shells.
Teacher. This would be one inducement,
but there are many more important advantages
connected with classification. Suppose that you
had found a variety of shells on the seashore,
and wished to inform a friend of the specimens
40 LESSON VIII.
you had picked up, without entering into a long
description of each, what would you do ?
Child. I would tell him their names.
Teacher. But if he had never seen the shells
before, what idea would the name convey to
him ? If I told you that I had a murex in my
hand, what notion would you form of this shell ?
Child. None at all, unless you shewed it to
me.
Teacher. But if you had seen the shell,
observed its peculiar form and appearance, and
been told that it was called a murex, what would
then be the effect of my telling you that I had
another murex in my hand ?
Child. I should know exactly what kind of
shell you meant.
Teacher. This will give you some idea of
the advantages of scientific classification. In the
various branches of natural history, those ob-
jects which resemble each other in essential
characters are formed into a class or genus, a des-
cription of their points of resemblance is drawn
up, and a name affixed to the class. When
we have become acquainted with these charac-
teristics, the name will recall to our minds the
idea of the set of things signified by it.
Child. A name then becomes very useful.
Teacher. How does it become so useful !
Child. By recalling to the mind the things
which it signifies.
Teacher. What is the class of objects which
you are about to study ?
SHELLS. 41
Child. Shells.
Teacher. In learning the names of shells you
will learn also what the names imply. The
science which treats of shells, is called Concho-
logy, from the Greek word KOVM (conch£) a
shell, and Xoyo<; (logos) a discourse. From whence
does the shell derive its shape and colour ?
Child. From the animal that inhabits it.
Teacher. What then do you think we ought
to study besides the shell ?
Child. The mollusca.
Teacher. Yes. But as we should not be
able to procure many of these animals, we can-
not pursue that branch of the science ; and we
will therefore follow the classification of Linnaeus,
which is founded on the shells. He first divides
shells into three great classes. Here are a large
number which I will arrange in three divisions,
and you must examine each, and observe in
what respect the shells I have classed together
resemble each other.
Child. The shells in one set are formed of
one piece, in the other of two pieces, and these
seem to have several pieces.
Teacher. These distinct pieces are called
valves. Where have you ever heard of a valve ?
Child. A pump has a ^ valve, — and steam
engines have valves.
Teacher. Can you tell me what is the use of
the valve of a pump ?
Child. To prevent the water from returning
into the pipe through which it has passed.
42 LESSON VIII.
Teacher. The animals of these shells with
two valves use these pieces for a very similar
purpose, — to exclude the water. Now that you
have found out the distinguishing character of
these classes, I will give you their names. Those
shells which are composed of only one valve are
called univalves, from the Latin, un us one, and
valve. Shells composed of two valves are
called bivalves from bis the Latin for twice, and
valve. Shells composed of more than two
valves are called multivalves, from mult us, the
Latin for many, and valve.
QUESTIONS ON THE MOLLUSCA
AND THE SHELL.
Questions will be given at each division of the subject,
which the children should be able to answer well without
assistance, before they proceed to a new part.
1. Describe the animals called mollusks.
2. Which of the different senses do they
possess ?
3. How do they move on land ?
4. By what means do they move in the sea ?
5. Describe the different methods by which
they render themselves stationary.
6. Describe the organs by which they feed
themselves.
7. Name the two classes into which the mol-
lusks are divided.
SHELLS. 43
8. Describe how the animals of these two
classes differ from each other.
9. Of what substances are the shells formed ?
10. How are they coloured ? and what is sup-
posed to occasion the regularity in the markings ?
11. How is the form of the shell regulated ?
12. What is there remarkable in the forma-
tion of shells ?
13. Give some examples of shells peculiarly
fitted for the different situations they occupy ?
14. Mention some instances of the compensa-
tory providence of God manifested in the history
of the mollusks ?
15. Into how many classes are shells divided ?
16. How are the shells of each class distin-
guished ?
17. Give the derivation of the names of the
classes.
LESSON IX.
PARTS OF AN UNIVALVE SHELL.
Teacher. To what class do all these shells
belong ? *
Child. To the class of univalve shells.
* A variety of univalve shells should be placed before the
party.
44 LESSON IX.
Teacher. I intend that you shall study the
univalve shells first, because they are the most
simple, and their distinguishing characters well
marked ; but before you can describe these
shells, you must be well acquainted with their
parts. Here are some univalve shells, — examine
them carefully ; I will give you the names for
the parts, as you discover them. First, tell me
which appear to be the principal parts.
Child. These shells have two principal parts,
this which swells out, and this which is tapering*
Teacher. The swelling part is called the
body,* and this which is tapering, the spire.
Observe how the spire is produced.
Child. It seems formed by the rolling round
of a part of the shell. f
Teacher. These parts that roll round are
called whorls, from an old Saxon word signify-
ing a round. What do you remark in these
whorls ?
Child. That they gradually increase in size.
Teacher. The largest forming the- body of
the shell is called the body whorl, the smallest
is called the first whorl. As the whorls succes-
sively roll one round another, what difference is
there in the circles they describe ?
Child. They gradually increase in diameter.
Teacher. It is from this circumstance that
the set of whorls is called the spire, a word
derived from the Greek root wceif, (speir,) which
* See plate I.
t See Helix Stagnalis. Plate V. Fig. 3,
SHELLS. 45
signifies convolutions gradually increasing in
diameter, just as would be the case in a rope
coiled up. In the coiled rope you have the cir-
cles rolled one within the other, and lying flat,
or being in the same plane. But if the centre
whorl is gradually raised above the rest, what
form do you obtain ?
Child. A conical form.
Teacher. Do you now perceive how the term
spire, originally derived from a word that sig-
nifies a set of whorls gradually increasing in
diameter, can be applied to a conical form ?
Child. Yes; because when the whorls rise
one above another, they produce the conical form.
Teacher. You will find the whorls in shells
arranged in both the ways described. When
the whorls are all upon the same plane, or nearly
so,* the spire is said to be refuse, a word derived
from the Latin, re, back, and tus us, beaten.
Tell me why this term is chosen, and pick out
some shells with retuse spires.
Child. I should think the spire is called
retuse, because the whorls appear beaten back
into the body.
Teacher. Exactly so; now look at some
specimens that form quite a contrast to these
retuse spires.
Child. Here are some in which the whorls
gradually taper to a very fine point ; what kind
of spire is this ?
Teacher. This very pointed spire is said to
* See Conus Marmoreus. Plate II. Fig. 1.
46 LESSON IX.
be subulate,* from the Latin subul a, a pointed
tool. The term spire is now applied to any
form resembling that produced by whorls, which
rising one out of the other, and decreasing in
diameter, though it be not occasioned by whorls.
You can, perhaps, recollect an instance in
architecture, in which the name is so applied.
Child. The spire of a church.
Teacher. When the spire of a shell is
formed by whorls, which is generally the case,
it is said to be spirally convoluted, the latter
term is derived from the Latin words, con to-
gether, and volut us rolled. Now examine the
spire still more attentively, and you will find
some other parts.
Child. There is a line formed where the
whorls meet ; has this line any particular name ?
Teacher. Yes, it is called the suture, from
the Latin sutura, a seam or joining; do you
perceive any difference in the sutures ?
Child. Yes, in some shells it is quite a ridge,
and in others it is more like a channel.
Teacher. When it is raised like a ridge or
keel, it is called carinate, from the Latin carin a,
a keel ; when it is a sunken line, it is said to be
channelled. Now look at your shells again.
Child. Are any parts of the shell considered
to be the top and bottom.
Teacher. Yes, the point of the spire is the top.
You recollect what the top and bottom of a cone
* See Buccinum Subulatum. Plate III. Fig. 4.
SHELLS. 47
are called, and you may apply these terms to
shells.
Child. The point of the spire is then the apex,
and the part immediately opposite, the base.
Teacher. You are right.
Child. I think that when you described to us
how the shells were enlarged, you called the
opening the mouth.
Teacher. Yes, it is termed either the mouth
or aperture.
Child. Shells have also sides.
Teacher. Yes, and it is necessary that you
learn to distinguish the two sides. You are
supposed, when you describe a shell, to place it
upon its base with its mouth turned towards
you ; the right side will then be that nearest
to your right hand, and the left that nearest
your left hand.
Child. What is the part turned toward me
called ?
Teacher. The front, and what do you sup-
pose the reverse is ?
Child. The back.
Teacher. Look at this section of a shell.*
Child. Is it cut down the middle that we
may observe the inside ?
Teacher. Yes ; and what do you perceive ?
Child. There is a pillar round which the
whorls appear to wind.
Teacher. This pillar is called the Columella,
from the latin colum ella, a little column.
* See Section of a shell. Plate I.
48 LESSON IX.
Child. Have we now mentioned all the parts ?
Teacher. No, you must examine your shells
more attentively.
Child. The edges of the mouth.
Teacher. By what name are the edges or
borders of our mouths called ?
Child. Lips. Is the same term applied to
the edges of the mouth of shells ?
Teacher. Yes, and you must distinguish
these two lips. What is their position ?
Child. One is on the outside of the mouth.
Teacher. That is called the outer lip, and
where is the other.
Child. Upon the body whorl.
Teacher. To which part of the shell is it
near ?
Child. It is near to the columella.
Teacher. It is thence called the Columellar
lip. In what respect do these lips resemble
ours?
Child. They are the borders of the mouth.
Teacher. Right. But how do they differ
from our lips ?
Child. They are not moveable.
Teacher. Do you suppose this is any disad-
vantage to the animal ?
Child. I should think it is, for he cannot
close his mouth, and exclude the water or keep
out enemies.
Teacher. True, but those species which
would suffer from such an exposure, are pro-
vided with a kind of lip which fits into the mouth
SHELLS. 49
and closes the entrance to the shell, when the
animal retires within it. This lid is called the
operculum, a latin word, signifying a covering.
The shells which are furnished with this appen-
dage, are said to be operculated. Did you ever
observe anything at all like it in the snails ?
Child. The entrance to the shell is guarded
by a thin covering during the winter.
Teacher. The animals belonging to land
shells, as for instance snails, protect themselves
from the inclemency of winter, by forming a
temporary covering, which adheres to the sides
of the shell, and is deciduous, — that is, falling
after a certain period, from Latin decido, I
fall. The operculum of the marine shell is
of a very different nature. It is either a calca-
reous or horny substance, is permanent, and not
attached to the shell, but to the foot of the
animal, who draws it over the mouth when he
recedes into his abode. Now tell me the position
of the mouth.
Child. It is on the right side of the shell.
Teacher. Observe whether that is invariably
its place.
Child. No, here is one shell it which it is on
the left side.
Teacher. This is the case in some few species,
and the shell is then said to be sinistral, a word
derived from the Latin sinistra, the left hand.
The others are called dextral shells, from dextra
the Latin for the right hand. The sinistral shells
are also said to be reversed, because the whorls
E
50 LESSON IX.
proceed in a direction contrary to their usual
course. Now look at this very singular shell.
(Murex haustelium.)
Child. It has a long tube.
Teacher. From what does it proceed ?
Child. From the mouth.
Teacher. Do you recollect any animals that
have a similar projection proceeding from their
mouths ?
Child. Oh yes ; birds, their beaks are like
this part of the shell.
Teacher. This projection in shells is also
called a beak, or rostrum, the Latin for beak.
Child. The beak is hollow.
Teacher. It is ; the interior is called the canal
and the shells which have these beaks are said to
be canaliculated ; and when the aperture has not
a beak or canal, it is called entire.
Child. Is the beak of any use ?
Teacher. Yes, the animals which have this
beak have an elongated fleshy tube, which is in
some way connected with their breathing.
Child. Many of the shells have projections,
some resembling thorns, some ridges, and
some rounded protuberances.
Teacher. The projections resembling thorns
are called spines, and the shells which have them
are said to be spinous. The rounded projec-
tions are termed tubercles, and the shells on
which they appear are called tuberculous. The
ribs which are longitudinal rounded sutures
formed at the various growths of the shell are
SHELLS . 51
called varices, from the Latin varix, a swollen
vein. But such parts as occur only in a few
species we will notice when we examine the
species. You must now repeat to me the parts
of a univalve shell, and I will write them on the
slate.
PARTS OF A UNIVALVE SHELL.
The spire,
whorls,
body whorl,
first whorl,
suture,
apex,
base,
aperture,
lips.
columellar lip.
outer lip.
columella.
body,
back,
front,
right side,
left side,
operculum.
Teacher. Describe to me each part and its
position.
Child. The spire is composed of the upper
•52 LESSON IX.
whorls, and is situated at the upper part of the
shell.
The whorls are the parts that roll round and
form the spire.
The first whorl is the smallest whorl, and is
at the top of the spire.
The body whorl is the largest whorl, and is
at the base of the shell.
The suture is the seam formed by the meeting
of the whorls.
The apex is the top of the spire.
The base is the opposite extremity to the apex ,
and is situated either at the lowest part of the
aperture, or at the end of the beak, when the
shell is canaliculated.
The aperture or mouth is the entrance to the
cavity of the shell.
The lips are the edges of the mouth.
The columellar lip is the lip nearest the
columella.
The outer lip is the outer edge of the mouth.
The columella is the pillar round which the
whorls form their spiral volutions.
The fron t is that part of the shell in which the
mouth is situated.
The back is opposite to the front.
The right side is that part of the shell which
would be next to the right hand of a person
looking at it, the front of the shell being placed
opposite to him.
The left side is that part of the shell which
would be next the left hand of the person
SHELLS. 53
looking at it, the front being opposite to
him.
Teacher. Give me the derivation and appli-
cation of the word spire.
Mention the different kinds of spires, with the
derivation of the terms which you use.
Whence is the term suture derived ?
How do the sutures vary ?
What different projections occur on the sur-
faces of shells ?
From what is the term varices derived ?
How are the cavities of the shells often
closed ?
Tell me the derivation of the word operculum.
What different kinds of opercula are there ?
What are the shells called which have a beak ?
What is the mouth said to be when it has no
beak ? *
* These model lessons have been drawn out with great
minuteness in order to exhibit two principles, very important
to be applied in this kind of instruction. 1st. That the object
itself should be presented to the children ; that their powers of
observation may be stimulated and directed by appropriate
questions ; and thus a considerable portion of their knowledge
be acquired by themselves, instead of all being simply
communicated by the Teacher. 2nd. That whatever supple-
mentary information is given should be reproduced by the
class before the conclusion of the lesson.
54
LESSON X.
Genus.— CONUS.— Plural, Coni.
CONE.
THE party should have before them a variety
of univalve shells, amongst which there should
be a large proportion of such Cones as have the
characteristics of the genus well defined.*
Teacher. I have brought a variety of shells
for you to examine ; what is the point of re-
semblance which unites them all in one class ?
Child. They are ail composed of one valve ;
they are all univalves.
Teacher. From these univalve shells select
those which appear to you to be similar in their
general appearance, and in the form of their
mouths.
Child. We have done so.
Teacher. Explain to me what you have done.
Child. We have selected those shells which
have the same general appearance, and a similar
kind of mouth.
Teacher. What was the common point of
resemblance in all the shells which I have set
before you ?
* It is very important in teaching children to draw out the
generic character of shells, to set before them specimens in
which the distinguishing features are strongly and clearly
marked ; their ideas will then be distinct, vivid, and perma-
nent. After this they may proceed to the examination of
shells, which, combining the qualities of different genera,
form the connecting links between them.
CONUS.— CONE. 55
Child. Their being composed of only one
valve.
Teacher. And what are the points of dis-
similarity that lead you to separate this smaller
set from the whole group ?
Child. The difference in their general ap-
pearance, and in their mouth.
Teacher. You have now formed a smaller
class. Such a subdivision is called a Genus,
from the latin word gen us, a kind ; the plural
of genus is genera. The characteristic distinc-
tion of each genus among the univalves is foun-
ded on the general appearance of the shells, and
the form of their mouth. The specimens which
you have chosen belong to the genus called
Conus, the plural of which is Coni. You must
now examine the shells carefully and try and
discover in what respect they resemble each
other ; you will then be able to describe their
generic character, or mark those qualities pos-
sessed in common by them all, and which dis-
tinguish them from all other shells. How will
you set about this ?
Child. We must compare them together,
and put down those qualities which they all
possess.
Teacher. First consider their general ap-
pearance.
Child. Their shape is very similar ; it re-
sembles a cone.
Teacher. Yes, and it is conical, and from
hence they have received their scientific name,
Conus, and their common English name, Cone.
56 LESSON X.
Child. The name expresses very well the
appearance of the genus.
Teacher. It does ; but which is the broadest
part of a Cone ?
Child. The base.
Teacher. And is the base the broadest part
of these shells ?
Child. No ; quite the reverse.
Teacher. They are therefore said to be in-
versely conical.
Child. The cones are spiral.
Teacher. Observe how the spire is formed.
Child. By the whorls.
Teacher. And how are the whorls arranged ?
Child. They are spirally convoluted.
Teacher. Compare the spires of the Cones
with those of the other shells before you, and
tell me what you remark.
Child. The whorls scarcely rise one above
the other.
Teacher. You remember what a spire is
called when the whorls have the appearance of
being pushed into the body whorl.
Child. Such a spire is called retuse. Here
is a Cone in which the upper whorls appear so
pushed into the body whorl that the spire forms
almost a flat surface.
Teacher. What then is the character of the
spire of the Cones.
Child. The spire of the Cones is retuse.
Teacher. Compare together all the different
shells before you, and you will find that the
CONUS— CONE. 57
relative proportion of their parts varies very
much. In some you will perceive that the
mouth is particularly large, in others the spire.
What is the relative proportion of the parts of
the cone ?
Child. The body whorl is very large, com-
pared with the other whorls.
Teacher. This peculiarity is expressed by
the term turbinate which is derived from the
Latin word turbin is, of a whirlwind.
Child. Why is this form of a shell named
after a whirlwind.
Teacher. Because the first sweep of a whirl-
wind describes a circle much larger than those
which succeed when its power is in some degree
exhausted. Do you not now perceive how
the term is applicable to the form you were
describing ?
Child. Yes. The body whorl is very large
in proportion to the others, just as the first
sweep of a whirlwind is large compared with
those that succeed it.
Teacher. You have now observed the general
appearance of the Conus ; what particular part
were you to take into consideration in order to
draw out the generic character ?
Child. The mouth.
Teacher. And what do you observe in the
mouth of the Cones ?
Child. It is long and narrow.
Teacher. When the mouth is very narrow in
proportion to its length, and also of a nearly
58 LESSON X.
equal breadth throughout, it is called linear,
from its having the character of a line. In con-
sidering the parts of an object, what besides
their form strikes your attention ?
Child. Their position and direction.
Teacher. You remember the usual position
of the aperture.
Child. It is almost always dextral or on the
right side of the shell.
Teacher. And as this is its usual position, it
is not noticed in the generic character, indeed
the peculiarity of a sinistral aperture never runs
through a whole genus of shells. But what do
you observe with regard to the direction which
the mouth of the Cone takes ?
Child. It is in the direction of a line passing
from the apex to the base, that is the length
of the shell.
Teacher. And what do you call the direction
of a line passing from the top of a body to its
base?
Child. Longitudinal ; the aperture of the
Cone is longitudinal.
Teacher. You recollect learning in a former
lesson the proper term for shells with a beak,
and also for those without one.
Child. Yes, those with beaks are called
canaliculated, and those without entire. The
mouth of the Cone is entire.
Teacher. Yes. A little experiment will lead
you to detect another characteristic of this
genus. Observe, I fill this shell (a Turbo) with
CONUS— CONE. 59
water to the edge of the lips — has any of the
liquid run over ?
Child. No ; the shell holds the water like
a cup.
Teacher. When this is the case, the mouth
is said to be contracted. But observe what is
the consequence when I attempt to fill a cone
with water up to the lips.
Child. The water runs out before it reaches
the lips.
Teacher. Examine where the liquid flows
out, and what is the cause of this difference in
the two shells.
Child. The water flows out at the base of
the cone. In the other shell the lips are united ;
in the cone they are separated by a small
channel.
Teacher. This channel is called a sinus, from
the Latin sin us, a curved line. If the two
lips be separated by a sinus, liquid poured
in overflows before it reaches the lips ; the aper-
ture iii this case is called effuse, from the
Latin fus us, which signifies poured out. You
have no doubt heard the term effusion applied
to the overflowing of any liquid ; you ought now
to know exactly what such an expression means.
Compare the columellar lip with the correspond-
ing part of the Cone in these shells (a Voluta
and a Cypraea.)
Child. It is smooth.
Teacher. Examine all your Cones, and see
whether they are all quite smooth.
60 LESSON X.
Child. No : there are stripes at the base of
some of them.
Teacher. These are called strice, the Latin
for stripes. Are they only perceptible to your
sight ?
Child. I can feel them also.
Teacher. What kind of striae must they be
if you can perceive them by your touch ?
Child. They must be raised.
Teacher. Yes ; they are slightly raised like
wrinkles, on which account they are called
rugose stria, from the Latin rug a, a wrinkle.
What direction do they take ?
Child. An oblique direction.
Teacher. The columellar lip is nevertheless
called smooth, because it has but trifling eleva-
tions. How would you describe the columellar
lip of a Cone ?
Child. The columellar lip of a cone is smooth.
except that it is marked by a few oblique rugose
str'uE.
Teacher. Remember that the stripes are only
occasional, not invariable. Do you think that
any quality in these shells has escaped your
observation ?
Child. They are all prettily marked and
have a beautiful polish.
Teacher. True; but the colours of shells
and the peculiarities on their surfaces are not
spoken of in the generic character ; these form
the distinctions of the different species. We
will now sum up what has been said respecting
CON US— CONE. 61
the Cones, and thus draw out their generic char-
acter. You must first mention to which of the
three great classes they belong ; next their
general appearance ; and lastly, the form and
peculiarities in the aperture.
* Genus— CONUS— Plural, Coni.
Generic Character. Shell univalve ; whorls
spirally convoluted, spire retuse ; form inversely
conical, turbinate ; aperture linear, longitudinal,
entire, effuse at the base ; columellar lip
smooth, sometimes marked at the base with a
few oblique rugose striae.
LESSON XI.
REMARKS ON THE SHELL AND ITS
INHABITANT.
Teacher. The genus Conus is very easily
known by its conical form and smooth columel-
lar lip ; these may be considered its two distin-
guishing characters. Much has not been dis-
covered of the history or habits of the mollusks
The generic character should be written on the slate be-
fore the children ; they should learn it, and afterwards occa-
sionally repeat it.
62 LESSON XI.
belonging to these shells. I will relate to you
all the facts that I have been able to collect,
and you must give your undivided attention to
what I say, in order that you may afterwards
write down the account from recollection.
The animal inhabiting the shells belonging to
the genus Conus, breathes by means of gills ; it
has two tentacula bearing eyes, the mouth is a
long proboscis, and the foot is furnished with an
operculum, by which it closes the entrance to
its shell. The section of a Cone displays a
fact very interesting, from its illustrating the sin-
gular habit of the mollusks ; it is, that the
internal whorls are of a much thinner substance
than the external coating. It is supposed that
when the animal by an addition to its shell,
causes what was its outer whorl to be surrounded
and concealed by a new one, that it absorbs a
portion of the old whorl, and thus it diminishes
the weight of its shell, gives more room within
for its body, and preserves the solidity and
strength of its bulwarks. In this we see a beau-
tiful instance of the superintending providence
of God, who by the instinct he implants, directs
the habits of the animal kingdom. The shells
of this genus are remarkable for the regularity
of their form, the brillancy of their colours, and
the beautiful variety and distinctness of their
markings. They are usually covered with a
thick epidermis,* which preserves the fine polish
Epidermis, art outer skin, from the Greek CTTI, (epi) upon,
(derma) a skin.
CONUS— CONE. 63
of the surface. They are all natives of the
ocean, and are taken in the seas of hot climates
where they live at a depth of about ten or
twelve fathoms.* They are never found on our
coasts. Their name is derived from the Greek,
Kuvoq (conos) a cone. Now attend and answer
the questions I shall put to you upon all that I
have detailed. What kind of animal inhabits
the cone ?
Child. It is one that breathes by means of
gills ; has a pair of tentacula bearing eyes ; and
its mouth is a long proboscis.
Teacher. There is one part of the animal
which you have not noticed.
Child. It has an operculum attached to its
foot, with which it closes the aperture of its shell.
Teacher. What is remarkable in the habits
of this rnollusk ?
Child. It is supposed to absorb the matter
of which the interior convolutions of its shell
are composed.
Teacher. What then is the appearance of
the shell when cut in halves ?
Child. The interior parts of the whorls are
thin, whilst the outer part of the shell is thick
and strong.
Teacher. What advantage is the animal sup-
posed to derive from the external convolution
being so much thicker than those within the
shell ?
Child. The thinness of the interior diminishes
* A Fathom is six feet.
64 LESSON XL
the weight, and gives room for its body, whilst
the thickness of the exterior preserves its strength.
Teacher. What is there remarkable in the
appearance of these shells ?
Child. They are remarkable for the regular-
ity of their form, the brightness of their colours,
and the variety and beauty of their markings.
Teacher. What is their appearance when first
taken out of the ocean ?
Child. They are generally covered with an
epidermis, which preserves their beautiful polish.
Teacher. To what seas do they belong ?
Child. To the seas of warm climates.
Teacher. And what is their situation in the
ocean ?
Child. About ten or twelve fathoms under
water. How much is a fathom ?
Teacher. A fathom is six feet; how many
feet then are they under water ?
Child. Between sixty and seventy feet.
Teacher. From what is the name Conus
derived ?
Child. The name conus is derived from the
Greek KMQ<; (conus) a cone.
The Teacher should again read to the children the facts
connected with the natural history of the genus, and require
them to give an account in writing of all they have heard.
For fear of discouraging them in the outset, some assistance
may at first be given ; but it should be gradually withheld,
and the attention brought into vigorous activity, that the mind
may become able to grasp the subject brought before it. The
first object to be attended to in their composition, is fluency,
and this will be best promoted by allowing them to use their
CONUS— CONE. 65
LESSON XII.
Teacher. If any one were now to speak to
you of a Conus, what idea would the name call
up to your mind ?
Child. The name Conus would recall the idea
of a univalve shell, whose form is inversely
conical and turbinate ; the spire retuse ; whorls
spirally convoluted, aperture linear, longitu-
dinal, entire, effuse at the base ; its columellar
lip smooth, having sometimes a few oblique
rugose striae towards its base.
Teacher. Yes, all the shells before us posses-
these qualities, or they would not be Cones : —
but are they alike in all respects ?
Child. No ; they differ very much in their
colours and patterns, and also in their size.
Teacher. On account of this variety in the
shells possessing the same generic marks, the
different genera have been subdivided into
species, the characters of which are determined
by -the circumstances of colour, markings, size,
own expressions, and follow their own arrangement of the
subject. When they have learnt to express themselves readily,
they should be taught to seek for appropriate language, and to
correct the inaccurate and inelegant expressions in their com-
positions. They should also be instructed to consider their
subject well, before they begin to write on it, that they may
arrange the matter in the best order.
F
66 LESSON XII.
and the inequalities of the surface. Here is a
shell called Conus marmoreus : 1 wish you to
examine it, and draw out its specific character ;
it is considered as the type or representative of
the Conus, from its having the characteristics
of the genus strongly marked. Now, tell me
what you have to do.
Child. We must try and describe this shell.
Teacher. Yes ; but you must recollect that
you have to point out the specific distinctions
only ; you must now omit the generic marks, as
you have already determined them, and they are
implied in the name Conus. First, what is the
size of this Cone? *
Child. It is rather more than two inches long.
Teacher. Yes, in length it generally varies
from two to three inches. What is the colour
of the shell, and that of its markings ?
Child. The ground is a dark chesnut brown,
approaching to black, and the markings are
white.
Teacher. What form do the spots most
nearly resemble ?
Child. They are nearly triangular.
Teacher. You may call them white subtri-
angular spots ; sub means under, and when pre-
fixed to an adjective implies that the quality
* The children should have the length of an inch given
to them, and by degrees they will learn to determine the
dimensions of the specimens without measuring them. They
should also be practised in deciding colours and their various
shades, by referring at first to some standard. Werner's
Nomenclature of colours is a useful work for this purpose.
CONUS— CONE. 67
attributed to the object, exists in an inferior de-
gree. Examine the substance of the shell.
Child. It is heavy and thick.
Teacher. It is a ponderous shell ; now look
at the spire, and tell me what you remark in it.
Child. It has little swellings placed regu-
larly at the edges of the whorls.
Teacher. These swellings are called tuber-
cles, and a spire marked with such inequalities
is said to be coronated.
Child. I suppose that means crowned.
Teacher. Yes, the spire is so called from its
crown-like appearance ; do you observe any
other peculiarity in it ?
Child. The whorls are concave, and in most
shells they are convex.
Teacher. The whorls in this shell form a
little spiral channel, and are thence said to be
channelled. We will now write down the specific
character ; but I must inform you, that the
name marmoreus is derived from the Latin
marmor, marble ; and is applied to these shells
on account of their mottled appearance.
CONUS Marmoreus*
MARBLED CONE.
Specific Character. Shell ponderous, smooth,
dark chesnut brown, with white sub triangular
spots ; spire coronated, whorls channelled ; size,
from two to three inches in length.
* Plate II. fig. 1.
F 2
68 UNIVALVES.
Genus.— CYPR^A.*— JVwraJ, CyprcecB.
Generic Character. f Shell univalve, involuted,]:
smooth ; form, suboval, resembling a coffee
berry, obtuse at both ends ; aperture linear,
longitudinal, extending the length of the shell,
effuse at each end ; lips curved inwards and
toothed ; the spire in some species just percep-
tible, in others its position marked by an um-
bilicus^
OBSERVATIONS ON THE SHELL AND ITS
INHABITANT.
The Cypraeae, of which there are numerous
species, display a high natural polish, uniformity
* Plate II. fig. 2, 4, 5.
*f* The proposed manner of imparting instruction upon
Natural History, so as at the same time to develop the faculties
of children, having been fully shown in the preceding pages :
the substance only of the lessons will now be given for the
use of the Teacher ', who, it is supposed, will analyse it and
arrange it in questions according to the plan of the fore-
going lessons. A frequent repetition of the generic character
is recommended, and also that the children be required occa-
sionally to give a list of the parts of a shell, and definitions
of the terms they use.
+ Involuted. Rolled inwards, this term is applied to a shell
when the first whorls are rolled within the body whorl, from
the Latin involut us9 rolled up in.
§ Umbilicus. A small hollow : this term was applied by
the ancients to the centre of the shield.
CYPRAEA— COWRY. 69
of shape, delicate and distinct markings, with
great beauty and variety of colours. They are
readily distinguished from all other shells by
their lips being rolled inwards, and both of
them toothed. The history of the genus is very
interesting from the remarkable difference which
occurs in the appearance of the same shell at
the various stages of its growth. In its earliest
state, the shell is very thin, almost colourless,
and dull ; the mouth rather wide, the outer lip
not rolled inwards, but having a sharp edge, and
neither lip denticulated. The shell which the
animal first forms is indeed so dissimilar to the
perfect Cypraea that it was formerly placed in
another genus. In the second, or intermediate
period of growth, the shell begins to approach
the general form that characterizes the genus.
The lips are curved inwards, and the teeth be-
come apparent; but the shell is still thin, its
colour faint, and its markings seldom more than
ill-defined tranverse bands. In its third and per-
fect state, the Cypraea has received an addi-
tional coating of testaceous matter, the pattern
appears with its vivid tints, and delicate mark-
ings, and the spire if not entirely hidden, yet
scarcely projects out of the body whorl.
The animal itself undergoes a considerable
change during its growth, its mantle at first is
small, but it increases with its age, and expands
at the sides into two ample wings ; from these it
is that the final layer which completes the shell
is deposited. In the adult specimens, these ex-
70 UNIVALVES.
pansions of the mantle completely cover the
shell, when the animal goes forth to seek its
food ; at the place where they unite, a longitu-
dinal line is formed, from its position on the
back of the shell, it is called the dorsal * line ;
when the wings are so large that they fold one
over the other, their place of junction is not
marked. The external polish of these shells is
owing to their being so frequently covered by
the mantle. The animals inhabiting theCypraea,
have a fleshy foot with which they crawl, simi-
lar to that of the snail ; the head is placed on a
neck, and has two finely pointed tentacula,
with two eyes situated at their base ; the mouth
is a round opening armed with teeth, these latter
are not only organs of nutrition, but defensive
weapons. The mantle in front forms a kind of
tube, which is lodged in the notch of the shell ;
through this the mollusk receives the water it
breathes. In a state of rest the Cypraete remain
buried under the sea at some distance from the
shore, but it is said that at full of the moon
they quit this retreat and traverse the rocks.
They belong principally to the seas of hot cli-
mates ; a few species are met with in temperate
regions, but these possess not the beauty of
colouring displayed by their congeners. f It may
generally be observed with regard to shells, that
* Dorsal, belonging to the back, from the Latin
the back.
f Congener — one of the same genus, from Latin con, to-
gether, andgenws. *
CYPRAEA— COWRY. 71
the intensity of their colouring decreases as their
locality approaches the poles. One species
called the Cypraea Moneta* is the current
money of Bengal, Siam, and Africa; it is
picked up by the negro women of the Indian
islands about the full of the moon. This genus,
on account of its great beauty, was formerly
dedicated to Venus, the fabulous divinity of the
island of Cyprus, from which circumstance its
name is derived.
CYPRAEA Arabica*
NUTMEG COWRY.
Specific Character. Shell subovate ; colour
brownish, or blueish white, inscribed with dark
brown markings resembling Arabic characters ;
the sides are thickened and spotted with purple ;
the teeth are chesnut brown ; the dorsal streak
is simple.
The shell is from two to three inches long,
the breadth is nearly three quaVters of its length.
The young shells of this species are blueish
grey, variously clouded or banded with brown ;
when the teeth are formed, the back appears of
a brownish or dull blue colour ; in this stage
of its growth, it has been known by the name
of Cypraea Amethystea, or the Smoke Cowry.
Linnaeus was not aware of the change in the
* Plate II. fig. 4. f Plate II. fig. 2.
72 UNIVALVES.
appearance of these Cowries at their different
periods of growth, and from this defect in his
knowledge, he has described the present species
under three different names.
CYPR^EA Eur&pea*
NUN COWRY.
Specific Character. Shell ovate, about half
an inch long, and a quarter broad, trans-
versely ribbed, the ribs terminating within the
lips ; of a pale purple or flesh colour, with
three dark spots on the ridge of the back.
This is a British species, and found abun-
dantly on our shores ; it greatly resembles the
West Indian species, but is distinguished from
it, in having no dorsal groove, and the dorsal
spots, if there are any, being limited to three.
Both the shell and the inhabitant vary so
much in their different stages of growth, that
much confusion has arisen in their classification.
The shell in its juvenile state is extremely thin,
brittle, pellucid, and quite smooth ; and the
animal of a pale colour, displaying no reflected
membrane. In its adult state the shell is thick,
opaque, ribbed, and when the animal is in
motion under the water, it extends over it the
lateral appendages of its mantle, which are
speckled with a variety of colours, presenting a
very beautiful appearance.
* Plate II. fig. 5.
BULLA— DIPPER. 73
Genus.— BULL A*— Plural, Bullcs.
DIPPER OR WATER BUBBLE.
Generic Character.-^ Shell univalve, convo-
luted, often without any spire, smooth ; J shape
suboval, inflated ; aperture longitudinal, gene-
rally the length of the shell, entire at the base ;
columella oblique, smooth.
OBSERVATIONS ON THE SHELL AND ITS
INHABITANT.
This genus is perhaps less accurately defined
than any other of the Linnsean genera : it contains
an assemblage of shells presenting a very varied
appearance ; indeed it seems as if it had been
formed to be a receptacle for including all the
species that could not find a place elsewhere.
The most distinguishing characteristic of the
Bulla is its gibbous or inflated figure, to which
it owes its name, signifying water bubble. One
* Plate II. fig. 6, 8, 9.
f It is hoped that Teachers who use these lessons will re-
collect that it is most important when the children are drawing
out the generic character, to bring before them a great variety
of shells, that they may group them according to resemblances
which they perceive, and under direction learn by observation,
their distinctive characters.
J The Bullae are said to be smooth because their surface has
never any projections.
74 UNIVALVES.
species (Bulla Ovum) bears a very striking re-
semblance to the Cypraea, it differs chiefly
from that genus by the absence of teeth on
the columellar lip. Some of the Bullae are
remarkable for having both ends of the mouth
produced into long beaks ; these shells are called
birostrate.* (Bulla Volva.) f
The inhabitants of many of the Bullae are
larger than their shells, in consequence they
cannot wholly recede into them ; indeed in many
the usual order is reversed, and the shell is so
surrounded and enveloped in the body of the
animal, that no part of it is visible, and an in-
experienced person would little expect to find a
regular testaceous specimen buried in an unsightly
slug.
A very remarkable circumstance in the animal
of the Bulla, is the form and structure of the
stomach, which is furnished with a gizzard ; this
organ is composed of three strong shelly pieces,
which have a roughness and prominency in their
centre, that fits them to grind whatever comes
under their action ; these plates are surrounded
and connected by a cartilaginous ligament by
which they are moved. It is supposed that such a
structure is necessary to the existence of these
mollusks ; for they are exceedingly voracious,
as is evident from the fact that the animal of
Bulla aperta has been found quite distorted from
* The children being acquainted with the words rostrum
and bis, will see at once the derivation of this word,
t Plate II. fig. 8.
BULLA-- DIPPER. 75
its having swallowed entire a shell nearly equal
in size to itself; not unfrequently shells are
found in their gizzard, reduced to a powder,
affording ample proof that it unites the two
offices of mastication and digestion.
The Bullae are not furnished with an oper-
culum ; indeed to many of the species it would
be a useless appendage, as the animal extends
beyond the shell, and cannot, on account of its
gizzard contract itself so as to retire within.
The marine species also reside in deep water,
and they are as safe there from crabs and other
enemies as the mollusks who live near the shore,
and barricade the mouth of their shells with their
opercula.
BULLA Lignaria*
WOOD DIPPER.
Specific Character. Shell oval, thin, brittle,
semi-transparent, yellowish or chesnut brown,
with numerous transverse striae of a light colour
approaching to white, giving it some resem-
blance to veined wood ; sometimes it has one or
two oblique bands ; inside white, glossy ; aper-
ture large, extending the whole length of the
shell, somewhat contracted towards the upper
part ; columellar lip smooth ; it has no external
* Plate II. fig. 6.
76 UNIVALVES.
convolutions, but at the top is depressed, and
has a small umbilicus ; it is usually about two
inches long, and one and a quarter broad at the
base.
This is one of the Bullae which possess a giz-
zard.* In this animal it consists of two trian-
gular, thin, testaceous plates nearly an inch in
diameter, and another of an elongated semi-
cylindrical form. These plates are connected
together by a tough yellowish ligament ; and
form a most powerful digestive organ ; when the
animal has been dissected, there have been found
in or near this gizzard, numerous specimens of
the smaller testacea, with their shells reduced
completely to a powder.
This is the largest species of the British
Bullae.
BULL A Fontinalis^
STREAM DIPPER.
Specific Character. Shell sinistral, having four
or five reversed volutions, glossy, pellucid,]: and
of a light horn colour ; the body whorl is large ;
the others are very small, and not much pro-
duced ; aperture oval oblong, three fourths of
the length of the shell. Old specimens are
* Plate II. fig. 7. + Plate II. fig. 9.
J Pellucid, so clear that the light is seen through it. From
Latin, per through, and lux light.
BULLA— DIPPER. 77
somewhat striated, and rather wrinkled longitu-
dinally, with two or three faint tranverse ridges
on the body whorl. Length in the largest
specimens, half an inch, breadth a quarter.
This is a British species, not unfrequently
found in stagnant pools and running waters, upon
the under side of the leaves of aquatic plants.
The animal is of a light yellowish colour, has
two long setaceous* tentacula, with two black
eyes placed underneath at their base. When in
motion, it covers great part of the shell with a
transparent membrane, scarcely perceptible to
the naked eye.
It has very considerable powers of locomotion,
and transports itself with the shell downwards,
by adhering to the surface of the water, crawling
over it with as much apparent ease as if it were
on a solid body. It can also let itself down
gradually by a thread which it affixes to the
surface of the water, as a caterpillar attaches
itself to the branch of a tree ; it is the only
animal that is known to be capable of thus sus-
pending itself under water. It has also the
power of throwing its shell about in an extraor-
dinary manner, whilst it keeps its body fixed by
its foot ; it probably resorts to this singular
habit either in self-defence, or to remove the
little aquatic animals with which it is tormented.
* Setaceous— "bristle shaped, from Latin seta, a bristle.
78 UNIVALVES.
Genus.— VOUJT A*— Plural, Volutes.
VOLUTE OR WREATH.
Generic Character. Shell univalve, spirally
convoluted ; shape suboval ; aperture narrow,
longitudinal, generally effuse at the base ; having
sometimes a dorsal notch ; columella has oblique
plaits, varying in size and number.
OBSERVATIONS ON THE SHELL AND ITS
INHABITANT.
This genus contains shells highly valued for
the beauty of their colours, and the brightness
of their natural polish. They vary considerably
in their appearance. Some have the aperture
entire ; in others it is effuse, terminated by a
notch, or produced into a canal ; the distinctive
mark however by which they may be immedi-
ately recognised is the plicated t columellar lip.
It is supposed that the animals inhabiting such
variously formed shells, must also be very differ-
ent, since it is found that the abode of a
mollusk is invariably suited to its conformation
and habits. There are but very few British
species of this genus, and even these are doubtful.
* Plate II. figures 10, 11.
•f Derived from Latin plica, a fold.
VOLUTA— VOLUTE. 79
The term Voluta signifies rolled up cylin-
drically.
One large family has been separated by modern
conchologists from the Volutes, and formed
into a distinct genus called Oliva, composed
principally of the Voluta Oliva* of Linnaeus.
These shells are of a cylindrical form, have a
short spire, and the aperture notched at the base.
They are easily distinguished from all other
Volutes, by having their whorls separated by a
channel. Their surface displays a fine polish,
and many of them are beautifully coloured. It
appears that the Olives are formed, like the
Cowries, of two coatings of testaceous matter ;
when the upper one is artificially removed, that
underneath often displays most beautiful tints.
They are found in hot climates. The animals
which inhabit them, breathe only water, which
they inhale by means of a tube situated under
the head, and fitting into the dorsal notch.
Another large family of Volutes are called
Mitres, from their resemblance to the insignia
of clerical dignity. These are now arranged in
a distinct genus bearing the name Mitra. Their
form is more elongated than that of their con-
geners, being f turretedor fusiform, and the apex
very pointed. They are also characterized by the
gradual decrease in the size of the collumellar
folds as they approach the base. These shells
* Plate II. fig. 10.
t The whorls gradually decreasing, the length of such shells
greatly exceeds their breadth.
80 UNIVALVES.
are as much admired for the brightness and
variety of their colours as for the elegance of their
form. They are found in the seas of hot cli-
mates. The natives of the Island of Tanna fix
them into handles and use them for hatchets.
The Voluta Epicopalis or Bishop's Mitre,* is
the type of this family. It is white, marked
with distinct orange spots. It is frequently
found in India. Its inhabitant is said to be of a
poisonous nature, and to wound with its pointed
proboscis any offender who ventures to touch it.
VOLUTA Musica.
MUSIC SHELL.
Specific Character. Shell oval, with pointed
tubercles on the whorls ; aperture emarginate,f
columella with eight plaits; outer lip smooth
and thick ; shell two or three inches in length,
colour white or buff ; it is remarkable for its
dark markings, arranged like a stave in music
in parallel lines, upon which are spots resembling
the notes; from this appearance it derives its
name.
* Plate II. fig. 11.
t Emarginate, notched, or having the margin excavated
by a sinus.
BUCCINUM— WHELK. 81
VOLUTA Pyrum.
TURNIP VOLUTA.
Specific Character. Shell pear-shaped, ponde-
rous, smooth, canaliculated, striated, and slightly
nodulous transversely; spire acute; columellar
lip with three plaits; colour dirty white; the
young shells are yellowish, and have irregular
transverse rows of dark spots. The size of the
perfect shell is about five inches long, and about
half as broad.
The reversed shells of this species are held
sacred in China, where a great price is given for
them ; they are kept in pagodas by the priests,
who on certain occasions administer medicine to
the sick out of them, they also use them to anoint
the Emperor at his ^coronation. They are often
curiously ornamented with carvings, executed
by the Indians, who use them for drinking cups.
Genus.— BUCCINUM.*— PZwraZ, Buccina.
WHELK.
Generic Character. Shell univalve, spirally
convoluted, frequently canaliculated ; form gib-
* Plate III. % 1, 2, 3, 4.
G
82 UNIVALVES.
bous ; aperture ovate, effuse at the base, ending
either in a notch, or a short canal abruptly
curved and turning to the left, that is, from the
outer lip ; columellar lip flattened.
OBSERVATIONS ON THE SHELL AND ITS
INHABITANT.
The characters which distinguish this genus
do not always occur in each species. The most
invariable mark of distinction is the direction of
the canal ; and should this fail, as is the case in
a few instances, the thick gibbous form or the
flattened columellar lip will still point out the
proper situation of the shell to be amongst the
Buccina.
One division of this genus is known by the
common name of Tuns ; their scientific name
is Dolium. These shells are thin, brittle, turbi-
nate, of an inflated or globular form, transversely
ribbed, the aperture is large, and has a notch
at the base. The type is the Buccinum Dolium.*
Many of the Buccina are called Helmets, f
and are distinguished by their inflated, turbinate
form, and by their short beak abruptly reflected ;
their columellar lip is thickened and spread over
the body whorl, forming a flat expansion ; their
outer lip is also revolute,J and often dentated ; §
* Plate III. fig. 1. t Plate III. fig. 3.
$ Revolute, rolled back.
§ Dentated : toothed, frpm Latin, dens, a tooth.
BUCCINUM.— WHELK. 83
their spire is retuse and marked at intervals by
curved ridges which are the permanent margins
of the former apertures, and are interesting, as
marking clearly the various stages of the shell's
increase. The Helmets are very common, and
many are remarkable on account of their size and
solidity. One species (the Buccinum Cornutum)
is more than a foot in length. These shells are
handsome and are often used as ornaments in
rooms. They are found mostly in topical seas, dis-
tant from the shores, in sandy bottoms where
the animal buries itself in search of prey. They
form the modern genus Cassis.
The most beautiful shells of this genus are
called Harps ; * they have an elegant shape, rich
tints, and usually a glossy surface ; their form
is oval, spire short, aperture large, notched at
the base, the inner lip is spread over a portion of
the body whorl, the outer lip is thickened and
rolled outwards. The animal produces this
thickened revolute lip at different periods of its
growth, thus forming a number of elevated
ridges on the shell. Such marks of increase are
observable in many other marine shells, and in
a few land species; but in none are they more
numerous than in the Harps. The effect
of these ribs is very rich and pleasing. The
Harps are found in the seas of hot climates,
particularly near the Isle of France. The genus
they now form is called Harpa.
* Plate III. fig. 2.
G 2
84 UNIVALVES.
Another very distinct natural group of this
genus consists of shells called Needle Buc-
cina,* a term which indicates their subu-
late form. They possess the characteristic
mark of the genus in the notch of the aperture
slanting towards the left, though their pointed
elongated shape gives them a very different ap-
pearance to that of the Buccina in general. They
are now arranged in a genus called Terebra.
The name given to this genus is derived from
the Latin buccina, a trumpet, and it is very proba-
ble that these shells furnished the first idea of that
instrument, for if the apex be pierced or broken
off, a variety of sounds may be produced by
blowing into it. Triton, the fabled trumpeter of
Neptune, is represented with one of these shells
in his hand, when he is supposed to be calling up
the river deities to attend their monarch. This
kind of trumpet is still used by the Italian
herdsmen to direct the movements of their cattle.
In a part of Wales also the farmers summon
their labourers in a similar manner, and the
deep and sonorous notes thus produced, breaking
in upon the silence of those mountainous districts
have a very striking effect. In Palestine the
bee masters enticed their bees with a whistle
made by means of some shell, (probably a Buc-
cinum) and led them from meadow to meadow
to collect their store of sweets. Isaiah seems to
refer to this custom when he prophecies the con-
* Plate III. fig. 4.
BUCCINUM— WHELK. 85
quests of the Assyrian monarch. " And it shall
come to pass in that day that the Lord shall
hiss (or whistle) for the bee that is in the land of
Assyria. And they shall come, and shall rest
all of them in the desolate valleys, and in the
holes of the rock, and upon all thorns and upon
all bushes." Isa.vii. 18, 19.
Various species of turbinated shells, chiefly
of the Buccinum or Whelk tribe, are picked up
on the shores of the Isle of Wight. They are
found tenanted not by their natural inhabitants,
who love the deep recesses of the ocean, but by
a species of Crab called the Bernard, or Hermit
Crab. This creature curiously exhibits the
wonderful operations of animal instinct, whilst
he exemplifies in a striking manner the resources
of a compensatory Providence. The hinder part
of his body is tender and naked, unprotected
by that shelly covering which guards his head
and anterior extremities ; he would therefore be
peculiarly liable to injuries were he not endowed
with a foresight that directs him most inge-
niously to provide against any accident. This
he effects by seeking for the roomy cavity of
some forsaken Whelk, and wriggling himself
into it, he maintains his hold by means of a
hooked claw, which he fastens to any projection
in the shell, while his head and front claws hang
out at the aperture. Thus secure, this little crab
continues till increased in size he is compelled to
abandon his retreat and seek for a tenement of more
ample dimensions ; at such times he maybe seen
86 UNIVALVES.
traversing the sands, searching with patience and
assiduity for another abode, and examining each
empty shell, till he meets with one better suited
BUCCINUM Harpa*
HARP SHELL.
Specific Character. Shell oval, turbinate with
longitudinal, acute, and curved varices; mouth
expanding, notched at the base ; outer lip re-
volute ; collumellar lip smooth, flattened ; va-
riously marbled or banded with fawn colour or
reddish brown ; size from two to three inches
long, and nearly two-thirds as broad.
There are several varieties of this species,
which is much distinguished for its beauty.
They are found principally in the Indian ocean,
also in the seas of hot climates. They are
furnished with a horny operculum.
BUCCINUM Undulatum.
WAVED WHELK.
Specific Character. Shell thick and coarse,
with seven or eight ventricose whorls, having
* Plate III. figure 2.
undulating * ribs both transversely and longi-
tudinally striated ; varies in colour from dirty
white to chesnut brown ; size from two to five
inches long, and more than half as broad.
There are scarcely any of our shores which do
not produce this shell. It is commonly taken
in dredging by fishermen, who either use the
animal for bait, or destroy it, under the suppo-
sition that it is very destructive to a large species
of scallop, insinuating its tail, as they term the
trunk, into the shell, and killing the inhabitant
for food. The old shells are frequently covered
with a brown epidermis, or rough extraneous
matter.
The animal has two conical tentacula bearing
eyes at their base, a short foot, to which is
attached a horny operculum, and a long trunk
that issues through the notch at the base of the
shell.
BUCCINUM Lapittus.
ROCK WHELK.
Specific Character. Shell ovate, thick, with
five or six whorls more or less striated longitu-
dinally, and transversely crossed with finer
irregular striae ; apex, small, pointed; aperture
oval ; outer lip waved or denticulated ; it is
usually of an uniform dirty white, or yellowish
* Undulating : wavy, from the Latin undul a, a small wave.
88 UNIVALVES.
colour, sometimes banded with brown or yellow.
Length rarely exceeds two inches, breadth one.
The animal that inhabits this shell has two
slender tentacula bearing eyes about half way
up on the outside, the ends of the tentacula as
far as the eyes are retractile * like those of snails.
Its mantle forms a tube through which it
breathes ; it has a foot with a horny operculum.
Near to its head, and lying in a little furrow, is
a white vein which yields a beautiful purple tint,
supposed to be that so long celebrated as the
Tyrian dye. In order to obtain this colour, the
vein is laid open with a needle, and is found to
contain a tenacious yellow matter like cream.
As soon as this fluid is put on any substance, as
silk, linen, &c. and exposed to the air, the yellow
assumes a brighter hue, but speedily turns to pale
green, then gradually becoming darker, until it
has obtained a blue cast, and from that it
changes to a purplish red, more or less deep
according to the quantity used. The succession
of the tints is accelerated by exposure to the rays
of the sun. The stain given by this animal fluid
seems to be indelible, bidding defiance to every
chemical process to obliterate it, and it might
therefore be most advantageously used as a
kind of marking ink.
The Buccinum Lapillus is one of the most
common shells upon our coasts, adhering to
rocks quite up to high water mark.
* Retractile, capable of being drawn back, from the Latin
re back, and tract us drawn.
STROMBUS— CLA W SHELL. 89
BUCCINUM Suhulatum.*
TIGER SPIRE.
Specific Character. Shell turreted, subulate,
smooth : colour white, tinged with yellow, red,
or brown, and marked on the body whorl with
three rows of squarish, dark, ferruginousf spots;
the shell is from three to six inches long, and
the breadth scarcely exceeds one eighth of the
length.
Genus.— STROMBUS.J Plural, Strombi.
WINGED OR CLAW SHELL.
Generic Character. Shell univalve, spirally
convoluted, canaliculated ; form suboval ; aper-
ture more or less dilated, ending in a beak
turning to the right, that is, towards the outer
lip ; the outer lip usually expanding into a kind
of wing, with a sinus near the base.
OBSERVATIONS ON THE SHELL AND ITS
INHABITANT.
The remarkable peculiarity in the shells of this
genus is their propensity to have their outer lip
expanded into a wing-like projection ; from this
* Plate III, figure 4.
+ Ferruginous, of the colour of iron rust, from the Latin
ferrug 0, rust. J Plate III. figure 5.
90 UNIVALVES.
circumstance they are sometimes called the
Alatae * or winged shells. In some species this
expansion is lobed, in others it is divided into
curious digitations f or claws, giving the shells
a resemblance to spiders or scorpions, whence
they have received their specific names. Some
are remarkable for a lengthened spire, and very
much resemble in form the Needle Buccinum ;
these now form the genus Terebra.
The distinguishing marks of Strombi are the
sinus in the outer lip near the base, and the posi-
tion of the beak. Like the Cypraeae, they vary so
considerably in their different stages of growth,
that the juvenile specimens are scarcely to be
recognised as belonging to this genus : at an early
period the outer lip is not expanded, and there
are no traces of claws ; subsequently the wing
spreads out, and the claws appear as short
open spouts ; and when the shell arrives at its
full size, these become solid hornlike projections,
often very long and curiously curved.
There are not more than two or three species
of the Strombus found on our coasts.
The inhabitant is little known, but it is sup-
posed from its second sinus or notch, and its
curious digitations, that there must be some
peculiar circumstances in its construction and
habits.
* Alatae winged, from the Latin ala, a wing,
f Digitations, projections in the form of fingers, from the
Latin digit us, a finger.
STROMBUS— PELICAWS FOOT. 91
STROMBUS Pes Pelicani*
PELICAN'S FOOT.
Specific Character. Shell turreted, finely
striated transversely ; spire tapering to a fine
point with ten tuberculated convolutions; the
body whorl has two rows of smaller tubercles
beneath the larger ones ; outer lip much ex-
panded, four-clawed, the upper claw extending
up the spire, the lower one forming the beak ;
the two middle ones are ribbed along the back
in a continued line from the rows of tubercles,
and underneath is a corresponding groove. The
shell is of a pale brownish flesh colour. Length
nearly two inches.
The Strombus Pes Pelicani is subject to
great variations in the different stages of its
growth. In young shells f the outer lip has not
assumed its peculiar form ; it first gradually
expands, then the claws appear, and finally it
becomes digitated. Shells are found in all the
intervening gradations between the young and
the adult specimen.
This species is rather common on many of the
coasts of Great Britain, it is chiefly met with on
sandy shores.
* Plate III. figure 5. f Plate III. figure 6.
92 UNIVALVES.
STROMBUS Ckbragra*
SAVAGE CLAW.
Specific Character. Shell ovate, turreted;
spire short, tuberculated ; outer lip having six
strong curved claws, the sinus not immediately
at the base ; mouth striated ; colour white
mottled with brown ; lips orange colour with
black and white stripes; outside generally
coated with a thin horny epidermis ; size about
five inches long and three broad not including
the claws, which are from two to three inches
long, the upper and lower ones curved in
opposite directions.
This Strombus also exhibits a very different
appearance at its various periods of growth.
Genus.— MUREX.*— PfcwaZ, Murices.
ROCK SHELL.
Generic Character. Shell univalve, spirally
convoluted, canaliculated, rough with spines,
* Signifying, savage claw, from the Greek words x*l§»
(cheir) hand, and ay go,, (agra) fierce or savage.
•f Probably named from the Latin, murex, the primary
signification of which seems to have been the sharp point of a
rock. Plate IV. figure 1, 2, 3.
MUREX— ROCK SHELL. 93
tubercles, foliations, or varices ; aperture oval
ending in a beak, either straight or turned
backwards. Some of the species are remarka-
ble for the great length of the beak.
OBSERVATIONS ON THE SHELL AND ITS
INHABITANT.
The very great variety which occurs in the
shells of this genus has caused them to be ar-
ranged under several divisions ; but the mark
by which a Murex, according to the Linnaean
definition, may be easily recognised, is the oval
shape of the mouth ; this being preserved even
when the aperture is terminated by a beak, as
instead of gradually contracting, it abruptly
opens into a canal. Besides this regularity in
the outline of the aperture, another distinctive
mark is that the beak neither inclines to the
right nor to the left*
The Murices are in general of an irregular
form, arising from their surfaces being covered
either with spines, tubercles, varices, or folia-
tions ; and from the rock-like and rugged ap-
pearance thus occasioned they derive their desig-
nation. Some of the shells of this genus are
remarkable for the singular extension of their
beak.
Many of the Murices are distinguished by
their thick protuberent rounded varices. These
shells have been divided into different genera
94 UNIVALVES.
according to the arrangement of these ornaments.
In one division the shells are distinguished by
having two varices in each whorl, which are con-
tinued in a longitudinal series on each side up
to the apex, giving them a flattened appear-
ance on the front and back ; the genus which
they now constitute is called Ranella* Frog,
from the resemblance of the shells to that animal.
The shells of another division f are distin-
guished by three rows of varices, sometimes ex-
panding into elegant foliations or lengthened
spines, these varices are so arranged that they
form three longitudinal raised lines taking rather
an oblique inclination towards the apex. It is
evident that the habits of the mollusca of these
two sets of shells must be different, for the situa-
tion of the varices of the latter proves that a
smaller portion is added to the abode at each
epoch of its growth than in the Ranella.
A third division J of this genus includes shells
ornamented by varices, not disposed in a con-
tinued series as in the other two classes. This
difference in the disposition of these protuber-
ances is occasioned by the piece which the
animal adds to its shell being more than half a
volution. The varices are consequently few,
and appear scattered over the shell.
* Plate IV. fig. 2. t Plate IV. fig. 1.
$ Plate IV. fig. 3.
MUREX— flOCfiT SHELL. 95
BRANCHED MUREX.
Specific Character. Shell oval with three
foliated varices ; beak short and truncated ; the
colour of this shell varies greatly ; it is some-
times of an uniform whiteness, sometimes pale
yellow, brown, pale red, nearly black, and
sometimes the whorls are of one of these colours,
and the foliations of another. Its dimensions
also differ greatly; it varies from two to five
inches, and is about half as broad.
There is a circumstance of unusual interest
to be observed in the manner in which this ani-
mal increases the size of its shell, and which
shews most admirably the regularity and beauty
of the laws of nature, and directs the mind to
the contemplation of the wisdom and power of
the Creator, who alone could teach these little
animals how to construct an habitation so per-
fectly adapted to their circumstances and situa-
tion. It will be observed that each periodical
increase of these shells consists of a piece which
surrounds about a third part of the last volution
already formed, which portion is terminated in
this species by a foliated, in some by a spinous
varix, it is obvious that these foliations or spines
must be in the way of the future increase of the
* Plate IV. fig. 1.
96 UNIVALVES.
shells, unless they could be removed from that
part which it is intended to cover ; the animal
therefore is furnished with the means, perhaps
by a solvent liquid, of eating away the lower
part of these projections; so that they become
detached and fall off by the time that he is
ready to form his new inner lip upon the space
which they occupy, thus forming a comparatively
smooth and even surface on which he is to spread
the testaceous matter, of which the addition to
his building is composed.*
It is principally in this genus that are found
the shells which yielded the celebrated Tyrian
dye, they were thence called Purpurae. An ex-
pression of Virgil implies that it was extracted
from the animals of this genus in his time ;
He says, " glowing with Tyrian Murex." The
Tyrians were the most successful among the
ancients in preparing and using this celebrated
colour. The Mediterranean supplied them with
the mollusks in abundance, and in order to pro-
duce the tint that was in highest estimation, a
bath of the liquid extracted from the animal of
the Murex was prepared : in this they steeped
the wool for a certain time, and when taken out
they immersed it in another boiler, which con-
tained an extract from the Buccinum alone.
Wool which had been subjected to this double
process was so highly valued, that in the reign
of Augustus each pound of it sold for about
* Sowerby's Genera of Recent and Fossil Shells.
MUREX— ROCK SHELL. 97
£36; this enormous price is not to be won-
dered at, as only a single drop of the colouring
fluid is afforded by each animal.
This beautiful and precious colour was held
in the highest estimation by the ancients,
and in some countries it was consecrated to
sacred purposes. Moses, under divine instruc-
tion, used purple stuffs for the furniture of the
tabernacle, and for the dress of the high priests.
The Babylonians arrayed their idols in robes
of splendid purple ; and such indeed was the
practice of the Pagans in general, many of whom
superstitiously believed that this dye had a
peculiar virtue, and was capable of appeasing
the wrath of their pretended gods.
Purple robes were also characteristic of regal
dignity, and by an imperial decree in Rome,
they were entirely restricted to the use of the
emperor, the penalty of death being inflicted on
any who dared to appear in habiliments of this
hue. The language of the day shews how ex-
clusively this colour is appropriated to the empe-
rors, for " to assume the purple," signified the
being elevated to the Imperial Throne.
Several different accounts are given of the
discovery of this dye ; but they all seem to have
originated in the simple fact, that a dog having
broken one of the shells, stained his mouth with
the colour, which excited the attention of his
owner, and led to an examination of the cause.
The vast heaps of fragments of shells found
about Tarentum, are supposed to be those from
H
98 UNIVALVES.
which the celebrated dye was extracted, and
seem to indicate that place as one where it was
prepared ; it has not been ascertained to what
species these shells belong.
MUREX TriMus.
THORNY WOODCOCK.
Specific Character. Shell subovate, with three
spinous varices : spines continued to the extrem-
ity of the beak, which is long ; between the
varices the shell is transversely ribbed and
slightly nodulous : the colour is dirty white,
or pale brownish white ; the shell is about three
or four inches in length, of which the subulate
beak occupies the larger part ; the breadth of
the body whorl is about an inch and a quarter,
or an inch and a half.
This shell is found in the Asiatic and American
seas, also in the Red Sea. It was first discovered
by a singular accident. A diver feeling a sharp
pain from something having pierced his foot, and
apprehending that it might proceed from the bite
of some venomous animal, immediately gave
the signal to be drawn up, when he perceived
that it arose from one of these shells, the thorns
of which had entered his flesh.
TROCHUS— TOP SHELL. 99
MUREX Tritonia.
TRITON'S TRUMPET.
Specific Character. Shell ventricose, with
alternate varices, and slightly elevated transverse
ribs, the interstices striated ; the whorls cre-
nated * at the suture ; columellar lip grooved ;
beak short and ascending; colour whitish, orna-
mented on the ribs with parallel curved reddish
brown spots, which are shaded off towards each
other ; columellar lip striped with dark brown ;
the length is a foot, sometimes sixteen inches,
and the breadth about half as much.
It inhabits the Asiatic seas, and those of the
Torrid zone in general. It is used by the
natives of New Zealand as a musical instrument,
and by the Africans as a military trumpet. It
is supposed to be the shell intended by Ovid,
when he describes the waters of the deluge
retiring on the sound of the trumpet of Triton.
Genus— TROCHUS ^—Plural, TrocU.
TOP SHELL.
Generic Character. Shell univalve, spirally
* Crenated, being notched, from the Latin cren a, the
notch of an arrow.
t Plate IV. figures 4, 5, 6.
H 2
100 UNIVALVES.
convoluted ; form more or less conical ; aperture
entire, quadrangular, sometimes approaching to
round, generally wider than it is long ; margins
separated ; columella oblique.
OBSERVATIONS ON THE SHELL AND ITS
INHABITANT.
Many of the Trochi so nearly resemble the
shells in the following genus Turbo, that it is
often difficult to discriminate between them. The
character by which the former are most readily
known, is the angular contour of the mouth.
Their true form is that of a pointed cone, capa-
ble of standing nearly perpendicular, or but little
inclined on its base. Some of these erect shells*
have their columella umbilicated, othersf are
imperforate. A few of the Trochi are elongated J
resembling in form the Needle Buccinum ; these
have an exserted columella, and when placed on
their base, fall on one side. These latter are
now arranged in the genus Pyramidella.
Many of the shells of this genus have their
outside rough with tubercles, and many are
covered with a thick epidermis, on the removal
of which a bright surface appears, shining with
iridescent colours. The animals which inhabit
the Trochi have no proboscis, but a mouth
armed with two jaws, and thence it is concluded
* Plate IV. figure 5. f Plate IV. figure 4.
£ Plate IV. fig 6.
TROCHUS— TOP SHELL. 101
that they feed upon vegetables ; the shell has
neither notch nor canal, and the mollusk no
siphon.
TROCHUS Perspective*
STAIRCASE TROCHUS.
Specific Character. Shell conical ; umbilica-
ted ; the umbilicus large, funnel-shaped, round
which the whorls wind spirally, having a cre-
nated margin; aperture nearly quadrangular;
shell flat underneath, longitudinally and trans-
versely striated ; colour greyish, beautifully
variegated with ochrous brown spots.
This shell is the type of the modern genus
Solarium. It inhabits the shores of Asia : fre-
quent about Alexandria.
TROCHUS Cvnchyliopkorus.
CARRIER TROCHUS.
Specific Character. Shell conical, coarse,
obtusely plaited ; whorls imbricated,! base con-
cave ; colour brownish white ; size an inch and a
half long, and an inch and three quarters broad.
It is a singular fact in the natural history of
* Plate IV. figure 5.
t Imbricated, tiled, from the Latin imbrex, a tile.
102 UNIVALVES.
this shell, that it accumulates, during its forma-
tion, different foreign substances, and is often
found covered with stones, coral, small shells,
and fragments of shells; on account of this
curious property, it has acquired the name of the
Carrier. It has not been ascertained how this
animal, during the formation of its shell, collects
these various substances; probably some very
tenacious matter is combined with its calcareous
secretions, so that, whatever comes in contact
with it before it is hardened, adheres to its
surface.
Genus— TURBO*— Plural, Turbines.
TURBAN-SHELL.
Generic Character. Shell univalve, spirally
convoluted, solid ; shape more or less conical ;
aperture entire, contracted, orbicular.
.OBSERVATIONS ON THE SHELL AND ITS
INHABITANT.
The shells of this and the preceding genus
are often so similar, that it is difficult to define
* Plate IV. figures 7, 8.
TURBO— TURBAN SHELL. 103
the boundaries by which they are separated ; the
mouths of the Trochi gradually losing the
angular, and assuming the orbicular form ;
whilst many species of the Turbines exhibit a
very imperfectly circular aperture.* Both names
also imply any thing that whirls round ; and the
shells in each genus agree in their conical form,
and in shewing no indication of an increase in
growth, after the first formation. Besides, this
general resemblance in their appearance, the
animals are nearly allied in their habits. The
marine species are found on rocks and craggy
shores, or on the sand, when detached by *a
storm from their customary abode.
There are several species of Needle or Screw-
shell among the Turbines ; they are distinguished
by their circular mouth, from those of a similar
form in other genera ; their shape is that of a
well-proportioned spire, formed by thirty or
forty whorls, gradually tapering from the base
to the apex, and terminating in a fine point.
There are upwards of seventy species of Turbines
among British shells, and several of them are
terrestrial. t One called Turbo Fasciatus, is
found so abundantly in a part of Cornwall, that
it is impossible to take a step without crushiing
numbers. It is the prevailing opinion that they
contribute much to fatten sheep ; they spread
themselves over the plain and hill near Whitsand
Bay, Cornwall, and the sheep which browse on
* Turbo, the Latin for a whirlwind ; trochus, a top.
104 UNIVALVES.
the short herbage, must devour a prodigious
quantity of these mollusks, which early in the
morning ascend the short blades in quest of food.
Some very small Turbines, are found abundantly
on old walls amidst moss.
TURBO Littoreus*
PERIWINKLE.
Specific Character. Shell strong, sub-oval ;
body- whorl large, the others, four or five in
number, small and nearly flat, separated only by
a fine line ; aperture suborbicular, outer lip
thin, inner flat and thick. When full grown,
this shell is nearly smooth and of an uniform
brownish colour, but the younger shells are more
distinctly striated and variously marked with
purple, white, yellow, or red bands ; size, about
three quarters of an inch long, and nearly
equally broad.
The Periwinkle is extremely abundant on the
shores of Great Britain ; it is often sold in our
seaport towns, and when boiled, eaten by the lower
classes. It is found on rocks usually above low
water mark. The Swedish peasants affirm, that
when the animals of this species ascend the rocks,
it is a sure sign of an approaching storm, for that,
prompted by instinct, they thus place themselves
* Littoreus is derived from the Latin word littus, a shore.
The littoral species are those which burrow in the sand, or
adhere to the rocks when left dry by the receding tide.
TURBO— TURBAN SHELL. 105
out of the reach of the dashing of the waves ; and
on the contrary, that when they make their de-
scent into the sand, is is an indication of a calm.
The mollusk of the Periwinkle is striped
with black ; it has two setaceous tentacula annu-
lated,* or streaked transversely with black ; the
eyes are at the base of the tentacula and are
very prominent.
TURBO Scalaris.^
WENTLE-TRAP.t
Specific Character. Shell turreted, with eight
rounded detached whorls, connected only by
elevated acute oblique ribs ; the aperture round,
outer line thickened, and reflected ; the colour
snow-white, sometimes pale flesh colour : the size
varies from an inch and half to two inches in
length. The aperture is closed by a horny spiral
operculum.
This elegant shell when perfect is valued at
a high price, on account of its rarity. The
numerous ribs mark the different periods of its
increase, and are in fact the reflected margins
of its former apertures, produced at its various
stages of growth. It is found in the warm seas
of the east. There is a shell which inhabits the
European and American Seas, and is found upon
* From annulus, the Latin word for a ring,
t Plate IV. figure 7.
J A corruption of the German windel-treppe, a winding
staircase.
106 UNIVALVES.
our coasts, though not abundantly., called Turbo
Clathrus, or False Wentle-trap.* It differs from
the true Wentle-trap principally, in having its
whorls contiguous. The inhabitant is one of the
animals that yield a purple dye : if kept some
days out of water it becomes sickly, and dis-
charges a most beautiful purple liquid. This
dye differs in many respects from that obtained
from the Buccinum Lapillus. It can be pro-
duced spontaneously from the mollusks ; the
colour when first it comes from this animal is
purple, and not of the same unalterable nature
as that obtained from the other. These shells
now form a separate genus called Scalaria.
Genus HELIX f— Plural, Helms.
SNAIL.
Generic Character. Shell univalve, spirally
convoluted, sub-diaphanous,f thin and fragile ;
aperture entire, contracted, sub-orbicular; body
whorl projects into the mouth, separating the
lips.
* Plate IV. figure 8. t Plate V. figure 1, 2, 3.
£ Diaphanous is from the Greek words 5ta, (dia) through
and Qaivw, (phaino) I appear.
HELIX— SNAIL. 107
OBSERVATIONS ON THE SHELL AND ITS
INHABITANT.
The shape of the Helix varies considerably :
some of the species exhibit quite a turreted
form ; * in others the whorls are arranged on a
horizontal plane,f so that the spire is quite flat-
tened, and the course of the volutions may be
seen either from the upper or under part of the
shell. Many display a form between these two
extremes; others again are turbinate, and of a
globose appearance. J
There is not, perhaps, any thing in animated
nature more abundant or universally diffused
than snails ; the butterfly alone can compete with
them in this respect. Snails are found in the
most barren and desert wastes. There are parts
of the great Sahara destitute of all manner of
herbage, except here and there a tuft of coarse
grass, or a solitary stunted laurel, which accord-
ing to the Psalmist's description, " withereth
before it be plucked up." Yet these parched
specimens of vegetation are sometimes quite
studded with snails. It has often been conjec-
tured, that snails were in part the food of the
Israelites, when they took their rapid flight from
Egypt; for the country, through which they
passed in their way to the Red Sea, is described
* Plate V. figure 3. t Plate V. figure 2.
J Plate V. figure 1.
108 UNIVALVES.
by one who traversed it, as having a herbage
underneath the trees and shrubs, which is com-
pletely covered with snails of a prodigious size,
and of the best sort ; and in that country these
animals are esteemed a delicacy.
Snails furnish a valuable article of food on
the shores of the Mediterranean, where they are
boiled in their shells, and served up with rice.
They possess nearly the same nutritious qua-
lities as oysters, and the use of them has often
proved efficacious in consumptive disorders.
The Helices which live on land become torpid
on the approach of winter, and generally cover
the mouth of their shell with an operculum.
Like that of other terrestrial mollusca, this
covering is not attached to the animal, but to the
shell, and is deciduous, acting only as a preserva-
tive against the cold of winter.
The history of this genus is very interesting
and instructive, affording a striking instance of
the superintending providence of the Almighty,
and his care for the peculiar wants of His crea-
tures ; though all things are at his command,
He is not prodigal of means ; He gives what is
required, and holds back what is needless. Upon
the animals who inhabit the rocky shores, or
bottom of the ocean, He has bestowed a thick
substantial covering; but to snails, the greater
number of which live on the land, or in stag-
nant pools, or peaceful streams, He has given a
thin and remarkably light shell, which, while it
affords ample protection to its inmate, offers no
HELIX— SNAIL. 109
impediment to its loco-motive propensities. Can
we see this beautiful adaptation to circum-
stances— this provision for the wants, and consi-
deration for the comforts of His creatures, and
not give the praise and adoration to Him, who
riding upon the wings of the winds, regards not
only the sons of men, but the meanest reptile
that crawls upon the earth !
HELIX Pomatia*
EATABLE SNAIL.
Specific Character. Shell nearly globular,
turbinate, with five rounded whorls strongly
wrinkled longitudinally ; aperture semi-lunar,
margin rather thickened, and turned a little
outwards ; the columellar lip much reflected
over the umbilicus ; colour dingy yellowish
brown, commonly with three faint bands on the
body whorl ; one of which continues, round the
next whorl ; size about two or three inches in
length, and nearly equal in breadth,
This is the largest species of land shell found
in England. It is not a native of this country,
but was originally introduced about the middle
of the sixteenth century, either as an article of
food, or for medicinal purposes. It is supposed
to have been first imported from Italy into
Surrey, by a Mr. Howard of Albury ; the animals
increased there prodigiously, and are now become
* Plate V. figure 1.
110 UNIVALVES.
the most common species about Box Hill,
Ashtead, and that neighbourhood. They were
introduced into Buckinghamshire as a medicine
for a lady who was in a consumption. They are
commonly used as food by the Roman Catholics
in many parts of Europe during Lent, and are
preserved and fattened for that purpose in large
reservoirs, the floors of which are covered with
herbs and flowers. These mollusks were among
the dainties of the luxurious Romans, who had
their Cochlearia or nurseries for snails, where the
animals were fed on bran and wine, till they in-
creased to such a size, that if we may credit
Varro, a shell has been known sufficiently large
to contain ten quarts of liquid. It is mentioned as
a remarkable fact relating to this shell, that
when the animal is in a diseased state, the spire
becomes much elongated.
HELIX Hortensis.
GARDEN SNAIL.
Specific Character. Shell subglobular, smooth,
diaphanous with fine transversely banded whorls;
aperture roundish, semiorbicular, the outer lip
slightly reflected ; the colour of the shell and
the bands are exceedingly various ; greatest
diameter less than an inch.
This is the most common species of snail. At
the approach of winter, it forms an operculum
of a coriaceous substance, composed of several
HELIX.— SNAIL. Ill
coatings, and finding a retreat at the roots of
trees, and under old walls, it braves the rigours
of the season. Its circulation is most remark-
ably sluggish, and its movements are correspond-
ingly slow; but the thick juices which prevent
its activity, enable it to bear the severity of
winter, so that no cold, however intense, has
been known to freeze it. Again these juices,
though they retard the progress of the animal,
furnish it by means of their viscidity, with the
power of travelling with its house on its back
up perpendicular ascents, or across horizontal
surfaces. Snails do not usually crawl out in
search of nourishment, except in rainy seasons,
or in damp shady places ; in time of drought,
they take their station under stones and leaves,
or in the cavities of the trunks of trees. The
eggs of the snail are round and white; and
covered with a soft shell, adhering to each other
in clusters ; the parent hides them with great
care in the earth.
HELIX lanthma.
VIOLET SNAIL.
\
Specific Character. Shell with four whorls
obliquely situated, subglobular, thin, fragile,
diaphanous : aperture subtriangular,1 the angle
formed by the upper and lower part of the outer
lip rounded ; columella straight, and elongated,
the inner lip turned back over it; colour violet,
112 UNIVALVES.
palest towards the summit : size an inch long,
the breadth rather exceeds the length.
This shell beautiful in its form and colour, is
still more interesting in its history, as displaying
another instance of the overruling care of the
Creator, and of his compensatory providence.
Unlike most fragile shells, its dwelling is the
stormy ocean ; but as the feeble reed bends to
the mighty wind, and rises unhurt when its
power is suspended, so this delicate shell offering
no resistance to the sea, rides upon its waves in
perfect safety ; and as if still more to diminish
its gravity, the shell has no solid columella.
It is always found floating upon the water, and
probably never visits the bottom, or willingly
approaches any shore. It is thus supported on
the surface, by means of a small cluster of
bubbles composed of transparent vesicles which
it can inflate with air at pleasure, and thus buoy
up its delicate bark. Every shell contains
about a teaspoonful of liquor of a most beautiful
red purple, which is easily discharged, as soon
as the animal is touched. It is said also to shine
by night with a phosphorescent light. This shell
had always been considered a Helix by Linneus
and others, until the time of Lamarck who
determined it to be necessary to place it in a
distinct genus. He ascertained that its inha-
bitant differed essentially from the snail. The
organ which in the snail is considered a foot,
was found not to be fit for crawling, but swim-
ming, being covered with the air bladders
NERITA—NERITJS. 113
before mentioned. It inhabits the coasts of
Europe, Asia, and Africa, and is common in
the Mediterranean. A few specimens have been
picked up on the Welsh coasts, but these were
probably driven there by storms.
HELIX Obscura.
SMALL BROWN SNAIL.
Specific Character. Shell sub-oval, rather
obtuse, opaque, with about six longitudinally
wrinkled whorls ; aperture roundish, lunar ; it is
of a brownish horn colour, and the outer lip
white, with a reflected margin ; length half an
inch, breadth one fourth, or one sixth. These
shells are usually covered with an epidermis,
which varies according to the situations they
occupy ; and the colour being regulated by that
of the substance to which they attach them-
selves, they thus escape observation.
Genus-NERITA.* Plural, Nerita.
NERITE OR HOOF-SHELL.
Generic Character. Shell univalve, spirally
convoluted, retuse, gibbous, flattish underneath ;
* Plate V. figures 4, 5.
I
114 UNIVALVES.
aperture simi-lunar ; columellar lip, truncated,
flattish, straight, and oblique to the axis of the
shell.
OBSERVATIONS ON THE SHELL AND ITS
INHABITANT.
There is no genus more easily distinguished
than that of Nerita. The semilunar aperture
and straight flat columellar lip are its decided
characteristics. There are a few species which
might pass for Turbines, the columellar lip not
preserving its straightness ; but even in these
doubtful shells it is flat, and therefore their
proper place in this genus is obvious. Some of
the species have an umbilicus ; and in some the
columellar lip is beset with strong teeth. The
Nerites are all either fluviatile or marine, the
former are thin and generally have a bright polish
on their surface ; nothing can exceed the beauty
and delicacy of the minature painting with which
many of them are adorned. When viewed
through a microscope the most highly finished
touches are discernible. They are worn as
ornaments by the Indians. They are now
formed into a new genus called Neritina. The
marine species are distinguished by their solid
substantial shells, often having elevated rounded
ribs. The animal has a short foot, and two
setaceous tentacula, having eyes at their base.
NERITA— NERITE. 115
NERITA Peloronta*
BLEEDING TOOTH.
Specific Character. Shell solid, thick, semi-
globular, turbiuate, imperforate, slightly ribbed
transversely ; spire flat ; aperture entire, semi-
lunar ; outer lip crenulate, inner lip rather con-
cave, with two or three large teeth and an irre-
gular saffron or blood-coloured spot in the
middle ; ground of the shell whitish or pale grey
with irregular black and red or purplish longi-
tudinal zig-zag markings : aperture white, and
throat pale saffron-colour.
The shells of this species inhabit the ocean
and are found in the West Indies, Red Sea, and
Mollucca Islands. The animal is furnished
with an operculum which opens and shuts at its
pleasure, like a door upon its hinges, having a
little prominence within the shell at the lower
end of the lip, between which and the inner lip
a small projection of the operculum slides as it
opens.
NERITA Corona.
Specific Character. Shell globose, striated ;
spire short eroded ; f body whorl large with a
* Plate V. figure 4.
t Eroded, gnawed out from Latin e, out, and rod ere, to
gnaw.
I 2
116 UNIVALVES.
transverse row of long spines ; generally coated
with a black epidermis ; length from half to
three quarters of an inch, about two thirds as
broad.
This shell has an operculum, which is testa-
ceous, covered with a horny epidermis of a
semicircular form, exactly closing the aperture,
and furnished internally with a dentiform appen-
dage, which, when the aperture is closed, lies
between a prominence at the lower part of the
aperture, and the end of the inner lip.
The columella, together with the inner part
of the spire, and even a part of the lip is absor-
bed by the animal, in proportion as it increases
in size, whence it appears to have no colu-
mella.
NERITA Littoralis.
STRAND NERITE.
Specific Character. Shell thick, smooth,
summit rather obtuse ; whorls four or five, body
whorl large, the others small and lateral ; aper-
ture lunar, rather inclining to oval ; columellar
lip not so flat as usual in this genus ; colour
various, commonly plain light or orange yellow,
red or brown, sometimes prettily mottled, or
marked with one or two paler transverse bands ;
size about three-fourths of an inch long, breadth
rather exceeding the length.
This species is extremely common on all our
HALIOTIS— EAR-SHELL. 117
shores, varying considerably in colour and
shape : its roundish mouth and accidental resem-
blance of colour have occasioned some speci-
mens to be described as Turbines*
Genus— -HALIOTIS.* Plural Haliotides.
SEA-EAR OR EAR-SHELL.
Generic Character. Shell univalve, ear-
shaped, open ; spire flat, lateral, retuse, nearly
concealed ; aperture almost as large as the shell ;
the disk, f excepting in one or two species, has
a series of perforations parallel to the collumellar
margin.
OBSERVATIONS ON THE SHELL AND ITS
INHABITANT.
The ear-like shape, the flattened spire and the
row of perforations on the disk readily distinguish
this genus from every other. The outside of the
shell is generally rough, worn or covered with
marine substances. The inside is enamelled with
mother-of-pearl, exhibiting a beautiful iridescent
play of colours. Each period of the shell's
increase is marked by a new hole, and till the
* Plate V, figure 2.
•j* Disk, a rounded surface, from the Latin, discus, a dish
or platter.
118 UNIVALVES.
final addition is made, there is a notch in the last
perforation m which the animal places its siphon.
When a new hole is opened, one toward the spire
is closed, and there are seldom more than seven or
eight unstopped at the same time. When the
Haliotides traverse the rocks, their shell is like a
reversed basin, and the circumference is bordered
by the foot of the animal, which is very large ;
the spire is at the posterior part as it advances.
In their repose they adhere to the rocks with
such tenacity that it requires the utmost force
to disengage them, though they can with the
greatest facility remove themselves. They are
always found near the surface of the water, and
in serene summer nights they feed on the vegeta-
tion which springs up on the shore. All the
shells of this genus are marine, as the name im-
plies, being derived from «X$ (hals) sea, and UTO,
(ota) ears. Most of the species inhabit the seas
of warm climates. They have no operculum.
HALIOTIS Tuberculata*
COMMON SEA-EAR.
Specific Character. Shell strong, thick, sub-
ovate, transversely wrinkled, striated longitudi-
nally, and tuberculated ; near the inner margin
is a ridge extending the length of the shell, and
* Plate IV. figure 2.
HALIOTIS.— EAR-SHELL. 119
terminating in one spiral turn at the end, a little
produced ; this ridge is beset with tubercles
which increase in size as they recede from the
apex ; the last six are open ; when cleared of
extraneous matter with which it is constantly
covered, the outside is of a reddish brown colour
frequently mottled ; the inside is a beautiful
mother of pearl. The outer lip forms a flat ridge
quite up to the spire, and is pearly like the
inside ; the length is from three to four inches,
the breadth between two and three.
These shells inhabit the deep ; and they are
sometimes thrown upon our southern coasts after
violent storms. In Guernsey they are found in
great plenty adhering to the rocks at the lowest
ebb tide. The animal is eaten, and forms a very
savoury dish ; the shells are used to adorn the
houses of the common people, in the plaster on
the outside of which they are studded, and their
pearly iridescence glitters beautifully in the
sunshine.
120 UNIVALVES.
Genus— PATELLA.*— Plural, Patella.
LIMPET.
Generic Character. Shell univalve, without a
regular spire, dilated, conical, entire, concave
beneath in proportion as it is convex above.
OBSERVATIONS ON THE SHELL AND ITS
INHABITANT.
The shells of this genus are easily distinguished
from all others by their conical form and dilated
aperture ; but they are subject to many pecu-
liarities, and are therefore divided into several
natural groups. Some are remarkable for an
internal chamber or partition, which however
varies greatly in its appearance. In the Patellae,
called the Slippers, it is formed by the columel-
lar lip, which is straight and produced into a
flat horizontal plate extending half over the
mouth of the shell ; these now form a genus
called Crepidula. In others, this appendage re-
sembles a cup and is situated at the apex within
the shell, which is commonly called from its shape
the Cup and Saucer Limpet ; f it is now sepa-
rated from the Patellae and forms the genus
Calyptraea. The apex of many of the Patellae
is perforated,! and this peculiarity in the shell
* Plate V. figure 7, 8, and Plate VI. figure 1.
f Plate V. figure 7. J Plate V. figure 8.
PATELLA— LIMPET. 121
is connected with a different formation of the
animal, whose gills are situated near the hole
through which it receives the needful supply of
water; these now belong to the modern genus
Fissurella ; others which have a fissure or notch
at the margin are called Emarginula. In some,
the apex is very retuse ; whilst in others it is
pointed and elegantly recurved.*
This genus is peculiarly interesting to those
who love to trace the regular, but almost im-
perceptible gradations existing in the scale of
nature. The species with the recurved apex
seem to form the link which connects the Patellae
with spiral shells, whilst the other species, where
there is no trace of any volutions, present the
intermediate grade between them and the shells
entirely destitute of spires.
The animal of the Patella has a large fleshy
proboscis, and two tentacula, with the eyes on a
small elevation at their base ; the mouth has
cartilaginous plates for the mastication of its
food. It has a ventral foot, fleshy, and fur-
nished with numerous muscular filaments, which
uniting on the upper part of the mantle, form
a strong muscle by which the body adheres to
the shell. By the action of this muscle, the shell
can be brought close to the surface to which the
foot adheres, or removed to a distance : and it
is by means of this instrument, that the animal,
when desirous of changing its situation, is able
* Plate VI. figure 1.
122 UNIVALVES.
to effect a considerable leap. Its locomotive
powers, however, are but little exercised : it
appears to live habitually in the same spot, and
rarely to perform any other movement than that
of slightly elevating the shell, that the water it
breathes may reach the respiratory organs.
These shells are generally found attached to
rocks, sea- weed, and other marine substances ;
and in such numerous clusters that the stones
appear quite studded with them; they, adhere
with considerable tenacity, and are not easily
displaced. They fix themselves thus securely,
by first applying their fleshy foot and the edge
of their mantle to the substance on which they
take up their abode ; and then they form an
internal vacuum by the contraction of their
muscles, and the pressure of the external air
keeps them firmly fixed to the spot. Thus ad-
hering to a solid basis, and presenting a shell
whose conical form is well calculated to break
the force of the rough winds and dashing waves,
this little animal in its exposed situation, exhibits
a striking instance of the wise provision of the
Almighty for the protection of his creatures.
This genus is found is all parts of the world, but
abounds particularly in the Island of Cyprus.
Its name signifies a little dish, an appellation
suggested by its form. The animal feeds on
sea-weed and marine vegetables. The manner
in which the Limpet attaches itself to the rocks
and thus seeks shelter, is beautifully described
and applied in the following verses ;
PATELLA— LIMPET. 123
6 In Nature's all-instructive book,
Where can the eye of reason look,
And not some gainful lesson find
To guide, and fortify the mind !
The simple shell on yonder rock
May seem, perchance, this book to mock —
Approach it then, and learn its ways,
And learn the lesson it conveys.
At distance viewed, it seems to lie
On its rough bed so carelessly,
That 'twould an infant's hand obey
Stretch 'd forth to seize it in its play ;
But let that infant's hand draw near,
It shrinks with quick, instinctive fear,
And clings as close as though the stone
It rests upon, and it, were one ;
And should the strongest arm endeavour
The Limpet from its rock to sever,
'Tis seen its loved support to clasp
With such tenacity of grasp,
We wonder that such strength should dwell
In such a small and simple shell !
And is not this a lesson worth
The study of the sons of earth ?
Who need a rock so much as we ?
Ah ! who to such a rock can flee ?
A rock to strengthen, comfort, aid,
To guard, to shelter, and to shade ;
A rock, whence fruits celestial grow
And whence refreshing waters flow —
No rock is like this rock of ours !
Oh then if you have learnt your pow'rs
By a just rule to estimate ;
If justly you can calculate,
How great your need, your strength how frail,
How prone your best resolves to fail,
When humble caution bids you fear
A moment of temptation near,
Let wakeful memory recur
To this your simple monitor,
And wisely shun the trial's shock
By clinging closely to your rock.'
124 UNIVALVES.
PATELLA Grceca.
CANCELLATED LIMPET.
Specific Character. Shell ovate, thick, opaque,
strongly reticulated,* some of the longitudinal
ridges much coarser than the rest, and frequently
tuberculated by the crossing of the transverse
striae ; apex lateral, not much elevated, trun-
cated and furnished with an oblong perforation ;
colour pale, dull brown, or yellowish white ;
inside smooth, white, sometimes rayed with dull
red or brown ; margin crenated, sometimes in-
dented ; length about three quarters of an inch,
breadth scarcely half an inch, height a quarter.
It is rarely found on the British coasts of a
superior size ; some of the foreign specimens
are an inch long. This shell belongs to the
modern genus Fissurella.
PATELLA Pellucida.
BLUE-RAYED LIMPET.
Specific Character. Shell sub-conical, thin,
pellucid, smooth; summit slightly recurved,
lateral ; of a dusky brown colour, rayed with
dotted lines of the brightest azure blue, lines
varying in number from three to seven ; length
nearly an inch, breadth not quite three-quarters.
This species is common in many parts of the
* Reticulated, crossed like net work, from the Latin,
reticul um9 a small net.
PATELLA— LIMPET. 125
Cornish and Devonshire coasts ; it is never found
adhering to rocks, but is picked up after
storms, having been thrown on shore by the
agitation of the waves, along with the sea-weed
to which it is attached. It is found in abund-
ance at Sandwich, and always on the same
plant, the stalk of which the animal excavates,
probably for food, and forms a cell, in which
are sometimes discovered two or three of the
same species together.
PATELLA Ungarica*
HUNGARIAN BONNET.
Specific Character. Shell conical, thin, semi-
transparent, finely striated longitudinally, and
wrinkled transversely ; summit much recurved,
and ending in two or three spiral turns ; it is
usually covered with a rough epidermis which
projects beyond the margin and forms a ciliatedf
border: beneath, the colour is reddish, the inside
glassy white, or flesh colour ; the base, which is
nearly circular, varies from one to two inches in
diameter ; the shell is rather more than half as
high.
This species, so remarkable for its elegant
form, is found on the western shores of Britain,
but is not common. It belongs to the new
genus Pileopsis.
* Plate VI. figure 1.
f Ciliated, bordered with a fringe like eye-lashes, from the
Latin cilia, an eye-lash.
126 UNIVALVES.
Genus— DENTALIUM.*— PZamZ, Dentalia.
TOOTH OR TUSK SHELL.
Generic Character. Shell univalve, gradually
tapering, straight or slightly curved, resembling
a tooth without any internal partition, open at
both ends.
OBSERVATIONS ON THE SHELL AND ITS
INHABITANT.
The shells of this genus are easily known by
their very simple construction ; they all more or
less resemble a miniature tusk, and the name
derived from the Latin dens, a tooth, refers
to this form. There are but few species, and
these vary principally in external appearance, in
magnitude, in the degree of curvature, and in the
ribs or grooves with which some of them are orna-
mented. One of the largest, called, Dentalium
Elephantinum is often three or four inches long,
and is strongly marked with longitudinal ele-
vated ribs. One species is so minute that it is
scarcely discernible by the naked eye, and resem-
bles a small bristle.
There is but little known of the inhabitant of
* Plate VI. figure 6.
DENTALIUM— TUSK SHELL. 127
tbe Dentalium ; some naturalists have supposed
it to be free, and independent of its shell, but
later observations have led to the discovery of
the muscle by which it is attached to its abode,
into which it has been observed to shrink deeply
for protection from approaching danger.
These shells are found principally on sandy
shores, sunk more or less deeply in the ground,
and placed in a vertical position.
DENTALIUM Entalis.
COMMON TOOTH SHELL.
Specific- Character. Shell slightly curved,
slender, tapering, smooth, glossy, sometimes
marked with a few circular wrinkles or annu-
lations, colour white or yellowish, length an
inch and a half ; diameter at the larger end two
tenths of an inch, and one fourth as much at
the smaller end.
It is commonly found on our coasts, particu-
larly those of the west of England. The animal
is very muscular, its shape is like its conical
shell, it has a mantle with a fleshy collar
through which it can protrude its head and foot.
Tne head is furnished with jaws, and lips bearing
teeth.
128 UNIVALVES.
Genus.— SERPULA.*— PZwraZ, Serpulas.
CREEPER OR WORM SHELL.
Generic Character. Shell univalve, tubular,
gradually tapering, usually adhering ; cavity
often interrupted by dissepimentsf at irregular
distances.
OBSERVATIONS ON THE SHELL AND ITS
INHABITANT.
These shells are usually found in very irre-
gular and diversified groups adhering to various
marine substances. They are invariably tubular,
and are either straight, or twisted ; sometimes
they are isolated and detached, but are more
frequently found in clusters consisting of hun-
dreds of spiral tubes curiously interwoven ; they
are sometimes curled into a spiral form, but,
differ materially from the convoluted shells, as
they never have any regular number of whorls,
or any appearance indicating that this mollusk
is directed in forming these convolutions, by an
invariable law. The name is derived from the
Latin serpo, I creep, and well designates their
tortuous t vermiform § appearance. There is very
* Plate VI. figure 2, 3.
•I* Dissepiments are the partitions in multilocular shells:
from the Latin sepes, a hedge, and dis, a prefix signifying
division.
J Tortuous, from the Latin tort ws twisted.
§ Vermiform, from vennis, a worm, and forma, a form.
SERPULA— WORM SHELL. 129
• little known of the animal. The Serpulae
abound in almost all situations that are at times
covered by the sea ; they are found attached
to various marine substances, from the firmest
rock and the sea-weed that grows upon it, to
sea-animals the most rapid in their motions. In
situations, where they are not subject to inter-
ruptions, they form patches of great thickness
and extent. Some of the rocks in the island of
Gorre are covered with a crust of them several
inches thick, and more than twenty feet square.
SERPULA Tubylaria.
TUBULAR CREEPER.
Specific Character. Shell taper, opaque,
slightly wrinkled transversely ; the smaller end
is usually convoluted irregularly, flexuous or
variously twisted, fixed ; the larger end fre-
quently detached for half its length ; diameter
at the larger end two-tenths of an inch ; length
four or five inches.
This is by no means a common shell ; it is
found at Tor Cross, Devonshire ; the head of
the animal inhabiting it is long, white, banded
with pink and green, and has two beautifully
feathered tentacula, originating from a single
stalk.
130 UNIVALVES.
SERPULA Aquaria*
WATERING POT.
Specific Character. Shell taper, straight,
with a convex disk at the summit perforated so
as to resemble the rose of a watering pot, having
also a radiated border : the colour is white with
a slight tinge of pale red or grey; the shell
when perfect is nearly a foot long, and more than
an inch in diameter at the dilated summit.
This most singular and beautiful shell is rare ;
it is found in the East Indies. It bears a great
resemblance to the spout and rose of a watering-
pot. It is now separated from the Serpulse
under the generic name Aspergillum.
Genus.— TEREDO. (Plural, Teredines.}
SHIP WORM.
Generic Character. Shell tubular, tapering,
flexuous, lodged in woody substances, with two
hemispherical valves, covering the head of the
animal, and two others of a lanceolate shape
near the extremity of the tail.
* Plate VI. figure 3.
TEREDO— SHIP WORM. 131
OBSERVATIONS ON THE SHELL AND ITS
INHABITANT.
Many doubts have arisen whether this genus
ought to be retained among the univalve shells.
Some naturalists consider the two hemispherical
valves as properly the shell of the animal since
it adheres to them by a strong muscle, and has
its head lodged in them, and they regard the
tube with the posterior valves as only accessory.
The use of the tube is to secure to the mollusk a
lubricated passage and a protection against the
rough surfaces of the wood in which it resides.
It is formed by a calcareous secretion, which
appears to have a solvent power over the resin,
and even over the fibre of the wood. Unless
this be the case it is difficult to account for the
fact, that these creatures pierce through the
stoutest oak timber, as they do not seem to
possess any organ sufficiently strong to effect
such perforations by a simple mechanical power.
On examining fresh specimens, a soft pulpy
mass of a chalky appearance, which hardens
when exposed to the air, has been discovered at
the opening of the hemispherical valves, and is
no doubt the secretion with which they lengthen
the tube. This is open at both ends, and
the animal does not in any way adhere to
it ; the posterior end is thickened and provided
with plates which contract the aperture, and
render it very small ; this part is always even
K 2
132 UNIVALVES.
with the surface perforated. Near the extre-
mity of the animal's tail are situated the two
lanceolate valves, they seem to perform the
office of flood-gates, admitting or excluding the
water as necessity may require. Linnaeus con-
sidered that the valves placed at both ends,
were of the nature of opercula, and that the tube
was the shell of the animal, which he conse-
quently placed amongst the univalves. The
name is derived from the Greek rcpeu (tereo) I
bore, expressive of the manner in which the
animal is supposed to effect a settlement in
different substances.
TEREDO Navalis.
COMMON SHIP-WORM.
Specific Character. Shell thin, brittle, straight,
or flexuous, tapering ; inside smooth, pervious ;
the smaller end thick and strong, furnished with
plates or laminae, which contract that part con-
siderably, and leave a very small opening ; the
anterior valves attached to the head of the
animal are of a hemispherical form, brittle, thin,
finely striated, and covered with a light brown
epidermis ; in each there is a long flat curved
tooth projecting inwards. The tube is white,
sometimes a foot long, seldom so long as the
animal ; the foreign specimens exceed greatly
in size those found in England.
This singular animal has proved exceedingly
TEREDO— SHIP WORM. 133
destructive to our shipping. It readily enters the
stoutest timbers, and ascends the sides of the
loftiest ships, most insidiously destroying them.
When the hulk of a ship is any time under
water, the Teredines appropriate it to their own
use, and soon commence the work of destruction,
They begin with the softest part, and at first
the apertures they make are so small as scarcely
to be perceptible. Their manner of carrying on
their labour is remarkable : they are careful
never to intrude upon the habitation of a neigh-
bour, and even where a piece of wood has been
so excavated as to resemble a honeycomb, no
communication or passage has been discovered
between the perforations, though often separated
only by the slightest lamina of wood. They
always bore in the direction of the grain of the
timber ; if they meet in their course with another
shell or knot, they make a turn ; when the obsta-
cle is small, they wind round it, and then proceed
onwards, but when large, rather than continue
any distance across the grain, they make a short
turn back in the form of a syphon. The attacks
of this insidious enemy have not been confined
to shipping ; our dock yards also bear sad testi-
mony to their work of devastation. In Holland,
where the inroads of the sea, and of the great
rivers by which that country is intersected,
have been restrained with immense labour by
dykes, the Teredines have proved very destruc-
tive, piercing and even destroying the piles
which sustained them.
134 UNIVALVES.
Many remarks suggest themselves in reading
the history of this animal. How insignificant
often #re the means employed to effect the most
important ends ; how is the industry of years
baffled by the gradual and yet certain work of a
little worm. We might at first be at a loss to
trace the wisdom or goodness of the Almighty in
permitting the existence of an animal fitted
only for what appears a work of evil. A further
acquaintance with the subject, will however
bring us to a very different conclusion. Mon-
tague, in speaking of them, says, " that the
Teredines and many aquatic animals were cre-
ated by the Father of the universe for most
beneficent purposes, cannot be disputed ; for
though they may seem to impede, and even to
destroy the operations of man, yet they are of such
importance in the great scale of nature, that it has
been observed, and it would not be difficult to
prove, that we should feel the loss of one or two
species of larger quadrupeds more than one or
two species of these destructive animals. The
immense trees and forests of tropical countries,
either overthrown by tornadoes, or partially
destroyed by insects, when carried by rapid
torrents into the rivers, would not only choke
them up, but even endanger the navigation of
the neighbouring seas, were it not for these small
yet powerful agents of dissolution. Nothing
can more plainly demonstrate the power of an
all-wise ruler of the universe than the work
assigned to these animals, whose business it is,
to hasten the destruction of useless matter."
SABELLA— SABELLA. 135
Genus.— SABELLA. (Plural, Sdbella.)
SABELLA.
Generic Character. Shell tubular, composed
of sandy or calcareous particles, and sometimes
fragments of shells agglutinated together, and
united to a membranaceous sheath by a cement.
OBSERVATIONS ON THE SHELL AND ITS
INHABITANT.
This genus is now very generally dismissed
from the class of Testaceous Mollusca, as the
tubes in which the animals are enclosed are more
or less composed of extraneous matter, and not of
a testaceous secretion prepared by the animal from
its own body, and forming a compact solid
substance, which is the true character of a shell.
Its best claim to retain its position, is, that the
mould to which the various particles are
attached, is really a calcareous and not an ani-
mal substance. The name of the genus is
taken from the Latin, sabulum, fine gravel or
sand, of which material their habitations most
usually consist.
136 UNIVALVES.
Genus.— NAUTILUS.*— (Plural, NavtiK.)
SAILOR.
Generic Character. Shell univalve, spirally
convoluted, smooth, multilocular ; f chambers
perforated and connected by a siphunculus or
pipe ; the dissepiments are convex inwardly, the
chambers gradually increase in size from the
apex. The animal resides in the last.
OBSERVATIONS ON THE SHELL AND ITS
INHABITANT.
The Nautili differ much in size ; some being
too minute to be observed by the naked eye,
while others are a foot in diameter. In some
the whorls are contiguous ; in others they are
detached. The tube which connects the chambers
is supposed to admit either air or water as the
animal requires ; when the shell is stationed at
the bottom of the sea the siphon is filled with
aqueous fluids ; by excluding these the gravity
of the shell is diminished, and it rises in conse-
quence to the surface; when on the contrary
the animal is inclined to descend, it contracts
* Plate VI. figure 4.
•f* Multilocular, having many little chambers, from the
Latin words, multus, many, and loculum, a little chamber.
NAUTILUS— SAILOR. 137
itself within its boat, draws in water, and imme-
diately disappears. Though capable of float-
ing on the surface of the sea, it is often found
reversed, and like a snail bearing its house upon
its back. The name is derived from the Greek
word vavnXos (nautilos) a sailor.
The animals inhabiting the shells of this and
the following genus vary considerably from the
other mollusca ; they are called Cephalopodes,*
(footed at the head,) because their heads are
surrounded by arms or tentacula. Their
bodies are fleshy like the other mollusca, and
the posterior portion is contained in the mantle
of the animal. The mouth is vertical and
armed with two corneous mandibles resembling
the beak of a parrot. They live in the sea,
are carnivorous, and feed on crabs and other
marine animals. The position of their arms
enables them to seize their prey, and bring it to
their mouth. The Cephalopodes which form a
multilocular shell, instead of being enclosed
within it, envelop it so as only to leave a small
portion visible : a tendinous thread which issues
from the extremity of the body appears to attach
the latter to the shell, it probably has some con-
nection with the siphunculus.
As in the genus Teredo we observed how
extensive a work of destruction is carried on by
a little worm, here we have to notice the reverse
Cephalopodes. Having feet on the head, from the Greek
(cephale) a head, and nodes (podes) feet.
138 UNIVALVES.
of that fact. A very small species of the
Multilocular Cephalopodes called Miliola (being
about the size of a grain of millet) exhibits the
power of reproduction in an equally astonishing
degree. Around Paris these shells are found in
the fossil state in such prodigious quantities,
that small as they are, they form the principal
part of the immense masses of stone which
constitute several of its quarries.
NAUTILUS Pcmpilius. *
LARGE CHAMBERED NAUTILUS.
Specific character. Shell with an involuted
and concealed spire, smooth; aperture cordate ;
colour whitish, with waved streaks of reddish or
yellowish brown, pearly within.
This beautiful shell is often converted by the
inhabitants of the East into a drinking cup ; on
the surface they engrave various ornaments and
devices.
NAUTILUS Spirula.
CROSIER NAUTILUS.
Specific Character. Shell thin, brittle, trans-
parent, with five cylindrical detached whorls
divided into numerous compartments, distin-
guished on the outside by a depressed circular
* Plate VI. figure 4.
ARGONAUTA— PAPER SAILOR. 139
line ; the last volution takes a straight direction,
and is remote from the adjoining one : aperture
orbicular, pearly within ; chambers separated
by their pearly plates, but communicating with
each other by a small siphunculus ; white or
cream colour.
This shell is so exceedingly brittle that per-
fect specimens are very rare. The last chamber,
which the animal inhabits, is a straight cylinder,
but it is so fragile that it is very seldom any
vestige of it is preserved. In the broken state
in which these shells are found, they resem-
ble a ram's horn, and so they have been descri-
bed, but when complete, they have more the
appearance of the crosier. The mouth of the
animal is surrounded by ten arms, two being
longer than the others. This Nautilus is found
in great numbers in the West Indies.
Genus.— ARGON AUTA.f (Plural, Argonautce.)
PAPER SAILOR.
Generic Character. Shell univalve, involuted,
the last whorl very large, having a double tuber-
culated carina, thin, transparent, unilocular ;
aperture cordate, entire, contracted. This shell
* Plate VI. figure 5.
140 UNIVALVES.
has much the appearance of being composed of
two pieces united by the keel, and seems to be
the link between the univalve and bivalve
shells.
OBSERVATIONS ON THE SHELL AND ITS
INHABITANT.
The animal inhabiting these elegant shells is
soft and fleshy, and has a large portion of its
body enveloped in the mantle ; its head is
furnished with two eyes, and round its mouth
are arranged like rays eight elongated and
pointed tentacula or arms. Two of these have a
thin membrane extending more than half their
length. This singular appendage the animal
can expand or draw in at pleasure. The shell
is of a thin paperlike substance, resembling in
form a kind of boat. Few objects can be con-
ceived more interesting than this beautiful animal
seated in its pearly little vessel : two tentacula
erected with their membrane unfurled like
a sail, whilst the remaining six, suspended over
the sides of the little bark, perform the office of
oars. When wafted by propitious gales, it
calmly rides over the waves : but should a storm
threaten, or an enemy approach, it precipitately
hauls in its tackle, shrinks into its shell, and
drawing in water to add to its weight, seeks
protection in the depths of the sea : the danger
over, it diminishes the gravity of its shell by eject-
ing the water, and rises again to the surface.
ARGONAUTA— PAPER SAILOR. 141
It has long been a doubt whether this animal
is the true inhabitant of the Argonauta, and it
is supposed by many naturalists to be one of
the eight-armed Sepia or Cuttle-fish, which,
like the Hermit Crab, having destroyed the
original fabricator of the shell, takes possession
of the vacated tenement.
How does this little animal verify the words
of the Psalmist, " They that go down to the
sea in ships, that do business in great waters,
they see the works of the Lord, and his wonders
in the deep." Ps. cvii. 23, 24.
The art of navigation, in the imagination of the
poet, owed its origin to the expert management
of these little instinctive sailors, whilst their
shell it is said, suggested the first idea of a vessel.
The name Argonauta, is derived from vam^c
(nautes) a sailor, and Argo, the name of the ship
in which Jason made his memorable voyage with
his companions the Argonauts.
ARGONAUTA Argo*
PAPER NAUTILUS,
Specific Character. Shell having a narrow
keel sharply toothed on both edges ; sides flat,
with undulated forked ribs ; extremely thin and
brittle; colour white, teeth of the keel brown
towards the apex. Inhabits the Mediterranean
sea, and Indian Ocean.
* Plate VI. fig. 5.
142 UNIVALVES.
QUESTIONS ON THE UNIVALVE
SHELLS.
1. What are the parts of an univalve shell ?
2. Give a description of each part, with the
derivation of the terms.
3. How is the genetic character of univalve
shells determined ?
4. How is the specific character of univalve
shells determined ?
5. Give a list of the genera of univalve shells.
6. Name those which have regnlar spires.
7. Name those without spires.
8. Which genera seem to connect the shells
with spires, and those without ?
9. What shells have longitudinal apertures ?
10. Which shells are canaliculated, and which
entire ?
11. Which of the univalve shells resemble
each other ? Describe their points of resemblance
and also in what respect they differ.
12. In what respect do the shells of warm
climates differ from those of colder regions ?
13. What is the generic character of the
Cone ? and what its distinguishing mark ?
14. What remarkable instinct is exhibited by
the animal of the Cone ?
15. Where are Cones found ?
16. What is the generic character of the
Cypraea, and what its most distinguishing mark ?
17. What is there remarkable in the manner
QUESTIONS ON UNIVALVES. 143
in which the shell of the Cypraea is formed, and
increased in size ?
18. What is the generic character of the
Bulla, and what its distinguishing mark ?
19. What remarkable organ is possessed by
the animal of the Bulla ? Describe the organ and
its use.
20. Describe the peculiar habits of the animal
of Bulla Fontinalis.
21. Give the generic character of the Voluta,
and its distinguishing mark.
22. Into what different families is the Voluta
subdivided, and how are they distinguished ?
23. What is the generic character of the
Buccinum, and its distinguishing marks ?
24. Describe the different groups into which
the genus Buccinum has been subdivided.
25. What is the origin of the name Buccinum ?
26. What use has been made of the Bucci-
num ?
27. Describe the habits of the Hermit Crab.
28. What is the generic character of Strom-
bus, and what its most characteristic mark ?
29. Describe how the shells called Alatae, or
winged Strombi, are increased at the different
stages of the animal's growth.
30. What is the generic character of the
Murex, and what is its distinguishing mark ?
31. Describe the different families into which
the genus Murex is subdivided, and mention
how the forms of these shells are connected with
the peculiar habits of their animals.
144 . UNIVALVES.
32. Which are the shells anciently called
Purpurae ?
33. Describe tfie manner in which the purple
dye was obtained and prepared, the different
uses to which it was applied, and the circum-
stance supposed to have led to its discovery.
34. What is the generic character of the
Trochus, and what its most distinguishing mark ?
35. Describe a remarkable peculiarity in one
species of Trochus
36. What is the generic character of Turbo,
and its distinguishing mark ?
37. Which species of Turbo is remarkable,
and on what account ?
38. What is the generic character of Helix,
and by what mark is it particularly distin-
guished ?
39. What variety of form is displayed in the
Helices ?
40. Detail the interesting facts connected
with the natural history of the Helix.
41. How does the Helix lanthina display the
compensatory providence of God ?
42. What is the generic character of the
Nerita, and by what mark is it readily known ?
43. What is the generic character of the
animal inhabiting the Haliotis ?
44. What is known of the habits of the
Haliotis, and what is its distinguishing mark ?
45. What is the generic character of the
Patella, and what its most distinguishing
mark ?
QUESTIONS ON UNIVALVES. 145
46. Describe the different groups into which
the genus Patella is subdivided.
47. What is there particularly interesting in
the natural history of the Limpet?
48. What lesson has the poet drawn from
their natural history ?
49. What is the generic character of the
Dentalium, and what its distinguishing mark ?
50. What is the generic character of the
Serpula, and its distinguishing mark ?
51. In what situations are Serpulx found,
and under what circumstances ?
52. What is the generic character of the
Teredo ?
53. WThat are the reasons for and against
retaining the Teredo amongst the univalve
shells ?
54. Describe the work of the Teredo Navalis.
55. What is the generic character of the
Sabella ?
56. What is the generic character of the
Nautilus, and its distinguishing mark ?
57. What kind of animal inhabits the Nau-
tilus ?
58. What is there remarkable in the natural
history of the Nautilus ?
59. What is the generic character of the Ar-
gonauta.
60. What position does the Argonauta appear
to occupy in the chain of nature ?
61. Describe the habits of the animal inha-
biting Argonauta.
146
BIVALVES.
The shells belonging to this class are com-
posed of two pieces united by an elastic horny
ligament :f the part where the valves are joined
together, is called the cardo, J or hinge, and
corresponds in position with the back of the
animal : it is either plain or furnished with teeth.
The ligament serves not only to connect the
valves, but also to open them, and is either ex-
ternal or internal ; the muscle or muscles by
which the animal is attached to the shell keep
it closed : when these are relaxed, the ligament,
which was either in a state of tension or com-
pression according as it was either external or
internal, by its efforts to recover its position,
opens the valves. If the two valves are quite
alike, the shell is said to be equivalve ; § if they
differ in form or size, it is called inequivalve.
If the sides of the valve are symmetrical, the
valve is said to be equilateral ; || if they are not, it
is said to be inequilateral.
* For the parts of a bivalve shell, see Plate I.
+ Ligament, a substance which serves to bind things toge-
ther, from the Latin, ligare, to bind.
J Cardo is the Latin word for a hinge.
§ Equivalve, having equal valves, from Latin, equ zts,
equal, and valve.
|| Equilateral, having equal sides, from Latin, *equ its
equal, and latera, sides.
BIVALVES. 147
The animals belonging to the bivalve shells
are acephalous mollusca, and have not a distinct
head ; they have no eyes, and the mouth, which
is hidden under the mantle, is only a simple open-
ing for the reception of food, without proboscis,
jaws, or any hard parts fitted for mastication.
This mouth is surrounded by four flattened
moveable expansions, which partake of the na-
ture of tentacula. The branchice,* or gills, con-
sist of two leaves or expansions on each side of
the mollusk, and extend the length of its body.
The mantle is large, sometimes it is quite open,
and bordered with contractile, irritable fila-
ments ; in some instances it is joined in front,
forming tubular elongations, called siphons,
which conduct the water to the mouth and
branchiae. The muscles are generally very
thick and strong, and hard at the place of attach-
ment to the shell ; those which close the valves
are called the adductor f muscles. Many spe-
cies have not the power of locomotion, but are
immoveably cemented to rocks or stones : a few
are attached by a cartilaginous ligament, others
by a byssus. These mollusca have no ventral
foot similar to that possessed by some of the
cephalous mollusca ; but some have a muscular
substance usually tongue-shaped and capable of
considerable elongation. This organ enables them
to creep, or to effect a kind of leap, by which they
* Branchiae, is derived from the Greek, jS^ayxm (bran-
chia) the gills of fish.
f Adductor, is derived from adduco, I bring together.
L 2
148 BIVALVES.
change the position of their shells ; sometimes
it is transformed into a paw, and sometimes
it is employed to fix the silky filaments of a
byssus. These mollusks do not appear to possess
the different organs of sense, but to be reduced
to that of touch ; indeed their faculties are
altogether much less developed than those of the
mollusca cephale. None of the bivalves are
terrestrial shells, some few are fluviatile. The
generic character of the bivalves is principally
derived from the formation of the hinge, and the
general appearance of the shell.
PARTS OF A BIVALVE SHELL.
The valves.
The cardo or hinge, the part where the valves
are united.
The beaks or apices, the points of the valves
near the hinge.
The base, the part of the shell opposite the
beaks.
The umbones or bosses, the swelled parts near
the beaks.
The ligament, the elastic horny substance,
which connects the two valves.
The margin of valves.
The area or anterior slope, the margin of the
valves near the ligament.
The areola or posterior slope, the margin of
the valves, the other side of the ligament.
MYA— GAPER. 149
The cavity.
The disk, the convex part of the valves
between the umbones and margin.
The length, the direction of the shell from the
beak to the base.
The breadth, the direction at right angles with
the length.
The auriculce * or ears, small appendages
placed at the sides of the hinge.
The circumference.
The muscular impressions, marks in the inside
of the shell made by the adhesion of the adductor
muscles.
The right valve, the valve nearest to the right
hand, when the shell is placed on its base with
the area opposite to the person looking at it.
The left valve.
The teeth, pointed protuberances at the hinge.
The cardinal teeth, the central teeth, or those
near the centre of the hinge.
The lateral teeth, the teeth near the sides.
Genus.— MY A.-\-— (Plural, Myce.)
GAPER.
Generic Character. Shell bivalve, equivalve,
* Auricula, a small ear; the diminutive of the Latin
auris, an ear.
f Plate VII. fig. 1, 2.
150 BIVALVES.
inequilateral, mostly gaping at both ends, gene-
rally smooth, or only slightly striated; shape
suboval, broader than it is long ; hinge with a
strong, patulous,* or spoon-shaped tooth, some-
times inserted into the opposite valve.
OBSERVATIONS ON THE SHELL AND ITS
INHABITANT.
The points of generic resemblance in the
Myae are wanting in many of the species. The
coarse large tooth is the characteristic of the
hinge, but sometimes it is not more than a
thickened callosity.f Some species are alto-
gether destitute of teeth ; these have a rounded
cavity for the reception of the cartilage. The
gaping of the valves is another distinguishing fea-
ture, but it does not always occur. In form
also the shells differ considerably ; some are
oblong and truncated, as if a part of the shell
had been cut off; others are orbicular, and many
are angular from the addition of ears at the hinge.
The Myae are generally covered with a thick
brown or green epidermis ; when this is removed,
the surface exhibits a beautiful iridescent
mother-of-pearl lustre. Some of the species
grow to a great size; others are remarkable for
* Patulous, lying open, spreading, from the Latin, pat ere,
to lie open.
*h Callosity, hardness of skin or flesh, from Latin call its,
which has the same signification ; hence our English word
callous.
MYA— GAPER. 151
their thick, solid, and substantial shells, and
have in consequence been formed into a distinct
genus, called IJnio. Many of the mollusks
of this genus burrow in the sand or mud, boring
a channel through which they thrust a con-
tractile trunk inclosing two tubes. The Myae
furnish food not only for man, but also for many
aquatic birds.
MYA Truncata*
TRUNCATED GAPER.
Specific Character. Shell ovate, convex,
truncated at the anterior end, where it gapes
considerably, curved at the areola, wrinkled
transversely, and covered with a brownish yellow
tough epidermis, extending an inch or two
beyond the gaping end, like a thick membrane,
through which the animal protrudes its tube ;
hinge with a rounded tooth projecting forwards;
inside white ; length from one to two inches ;
breadth from two to three.
These shells inhabit the sand or gravel about
low water mark on most of the northern coasts
of Europe. In Greenland, their mollusks are the
food of man and different animals. When taken
alive, the epidermis of the shell is found joined
to the tube or proboscis of the animal, having
* Plate VII. fig. 3.
152 BIVALVES.
become a thick, tough, coriaceous* skin for
its protection. The animal is capable of ex-
tending this tube to the distance of nine or ten
inches, and of contracting it to about three, but
cannot withdraw it entirely into the shell.
MYA Margaratifera.
PEARL-BEARING OYSTER.
Specific Character. Shell strong, ponderous,
thick ; shape ovate, oblong, front compressed,
margin a little contracted in the middle, giving
a somewhat curved outline to the circumference ;
hinge consisting of a cardinal tooth in one valve,
which is thick, obtusely conical, and locking
into a bifurcated f tooth in the other valve ; shell
about two inches long, and four broad ; covered
with a black epidermis decor ticatedj at the urn-
bones ; inside a greenish pearly hue.
This shell is one of a very interesting group,
now formed into a distinct genus called
Unio. It inhabits only rocky torrents, and
the precipitous streams of mountainous dis-
tricts. Many are found in the cataracts and
* Coriaceous, like leather, derived from the Latin cori urn,
skin, leather.
•f Bifurcated, having a fork of two teeth : from the Latin
bis, twice ; and furca, a fork.
J Decorticated, having the bark or outer skin taken off ;
from the Latin de, off : and cortex, the bark of a tree.
MYA— GAPER. 153
rapid rivers of America, and by their solid
and thick shells manifest the providential care
that fitted them for the dangerous spots they
occupy. When we look at the ponderous
Mya driven by the powerful torrent, and com-
pare it with the light and delicate lanthina,
borne gently on the surface of the waves, shall
we coldly attribute such adaptation to circum-
stances to the blind dealing of chance, and not
rather delight to recognise the beneficent wis-
dom of our heavenly Father, pervading all his
works, and suiting each animal to the place he
assigns it?
The Mya Margaratifera is found in several
of our rivers, particularly those of Wales ; also
in Ireland, where the peasantry use the valves
as spoons. This species has long been celebra-
ted for producing pearls of a good colour and
sometimes of a considerable size. These orna-
ments appear to be exclusively the production
of the bivalve testacea, and are found only in
the shells which have a coating of mother-of-
pearl in the inside of their valves. Pearls are
said to be produced by a disease of the animal,
occasioning a partial secretion of the sub-
stance, which forms the inner coating of the
shell. The British islands, especially Ireland,
have been noted for their pearl fisheries. The
Conway was formerly celebrated for this pro-
duction : a large one which was taken in that
river, and presented by Sir Richard Wynne the
chamberlain, to Catherine the consort of Charles
II. is said still to adorn the British crown.
154 BIVALVES.
Genus.— SOLEN *— (Plural, Soltnes.)
RAZOR SHELL.
Generic Character. Shell bivalve, equivalve,
gaping at both ends ; form oblong, transversely
elongated ; hinge has a subulate, reflected tooth,
sometimes double, not inserted into the opposite
valve. Most of the shells are brittle; some
have an internal rib extending from the hinge to
the opposite margin.
OBSERVATIONS ON THE SHELL AND ITS
INHABITANT.
There is in general but little difficulty in de-
termining the Solenes : they are recognized by
their oblong form, their disproportionate breadth,
and their gaping at both extremities. A few
of the species, however, are oval, and these
have their hinge nearly central. f
The history of this genus affords various in-
stances of ingenuity in the application of very
simple means. The mollusk is furnished with a
long pliable cylindrical leg ; when it wishes to
bore a hole for its residence, it extends this
instrument from the inferior end of the shell,
using it as a pointed shovel to excavate the sand.
When the tunnel is partly formed, the animal
* Plate VII. fig. 3, 4, 5. f Plate VII. fig. 5.
SOLEN— RAZOR SHELL. 155
advances the leg a little farther, fixes it by its
point as a hook in the ground, and using this as
a fulcrum, descends in safety, continuing the
operation till the shell is buried about two
inches under ground. When it wishes to regain
the surface, the leg is rolled up into a spherical
form, and stretched very tight ; by means of
the ball thus formed, the little creature is pre-
served from slipping backward, while by the
action of its muscular power, it throws the shell
forward. The peculiar habits of the Solen
render no other than perpendicular motion neces-
sary to it, and therefore while the form of its
shell, and the powers with which it is gifted, are
admirably calculated for movement in this
direction, it is unable to advance horizontally.
It requires a safe retreat and a supply of food ;
the former it obtains by withdrawing into its
recess, and the latter by ascending its channel
when the tide comes in and brings the little
marine insects which form its food. The
retreat of the Solen is marked by a small de-
pression on the sand ; sometimes the shells are
dug out by the fishermen, but as this is a labo-
rious employment, they are often entrapped by
stratagem. For this purpose, at the reflux of
of the tide, when the men can approach them, a
little salt is placed round their perforations,
which melting, is mistaken by the animal for
the return of the tide, and thus decoyed, they
elevate themselves in the expectation of finding
their prey. So rapid, however, are their actions
156 BIVALVES.
that great dexterity is requisite to catch them,
before they again sink into their retreat, and if
they are successful in escaping, they are not
easily tempted again to the surface. In many
places this animal is valued as food. The name
Solen, is derived from the Greek a-uXvjv (solen)
a tube. The French, in allusion to the shape
of the shells, call them manches de couteaux.
Several species of Solen are common on the
coasts of Britain.
SOLEN Siliqua*
POD RAZOR SHELL.
Specific Character. Shell straight, subcylin-
drical, truncated at one end, and slightly roun-
ded at the other ; hinge lateral, with a single
tooth in one valve, and a lateral rib locking
between two teeth in the other, which has also a
rib ; outside covered with an olive brown skin
striated transversely, each stria afterwards taking
a longitudinal direction ; beneath the epider-
mis the shell is greyish white with purplish
streaks; length about one inch, breadth from
one open end to the other, seven or eight inches.
This shell is common on most of our sandy
shores; it is found buried a foot or more in
depth near low water. In the neighbourhood of
Belfast, specimens of this shell are found more
than ten inches in length.
* Plate VII. fig. 4.
TELLINA— TELLEN. 157
SOLEN Radiatus*
RADIATED RAZOR SHELL.
Specific Character. Shell oval, smooth, thin,
brittle, striated concentrically ; when stripped of
its green epidermis, it appears both within and
without of a delicate violet colour, with from
two to four white longitudinal rays, which
become broader towards the margin ; hinge with
two teeth in each valve, and a strong white
depressed rib extending somewhat obliquely
from the hinge towards the margin ; shell about
an inch, or an inch and quarter long, and from
three to four inches broad.
It is found in the Indian Ocean.
Genus.— TELLINA.f— (P^mZ, TdRna.)
Generic Character. Shell bivalve, equivalve,
inequilateral ; shape either ovate and thickish,
ovate and compressed, or suborbicular ; the
area often compressed, having a flexuous plait or
fold, and its margin curved inwards, so that it
* Plate VII. fig. 5. f Plate VII. fig. 6, 7, 8, 9.
158 BIVALVES.
always narrower than the areola. The hinge
has either one or two central teeth in each valve,
one of them often bifid ; * the lateral teeth are
remote, and sometimes wanting in one valve ;
the beaks are short, and usually lean towards
the ligament, which is external.
OBSERVATIONS ON THE SHELL AND ITS
INHABITANT.
This and the following genus are so very
similar, that it is often difficult to discriminate
between them. If however a shell have its
anterior slope compressed, or any indication of
its margin being curved inwards, it may be
known immediately as a Tellina. The Tellinae
are very beautiful, and are particularly remark-
able for the coloured radiations with which they
are adorned. They have generally a fine polish,
and are sometimes delicately marked with minute
striae. They are found buried in the sand or
fine gravel of the sea shore; where they are
commonly the prey of Buccina, and other car-
nivorous mollusks, who pierce the shell, and
devour the inhabitant. The mantle of the ani-
mal is formed in the front into two siphons ; the
foot which it thrusts out of. its shell when de-
siring to change its position, is generally flat,
but sometimes it is straight and lengthened into
a kind of leg.
* Bifid, cleft in two, from the Latin bis twice, and fid z, I
have cleft.
TELLINA— TELLEN. 159
TELLINA Lingua Felis*
CAT'S TONGUE TELLEN.
Specific Character. Shell suboval, thickish,
somewhat angular at the anterior end, rough,
covered with pointed, rather arched erect scales,
disposed in a quincunx f order; colour white,
often with pale pink rays, and the umbones of a
fine pink ; length about an inch and quarter,
breadth about an inch and three quarters.
It inhabits the Indian Ocean.
TELLINA Radiata.
RADIATED TELLEN.
Specific Character. Shell ovate oblong, re-
flected at the anterior end, striated transversely,
highly polished ; colour sometimes wholly white,
more commonly white with red rays, or yellow
transverse bands ; the hinge is not central, it has
two small teeth in one valve, and one in the
other, and the lateral teeth are remote ; it is
about an inch, or an inch and half long, and
more than twice as broad.
* Plate VII. fig. 8.
f Quincunx, disposed alternately as in rows or spots, the
spots of each row being opposite the space between two spots
of the next row ; from Latin, quinqwe, five, and unx, ounce,
because the weight representing five ounces was stamped
thus X
160 . BIVALVES.
The Tellina Radiata is found very abundantly
in the West Indies ; it also inhabits the Euro-
pean ocean.
TELLINA Carnaria*
ROSY TELLEN.
Specific Character. Shell suborbicular, rather
more produced on one side than the other, sub-
pellucid, marked with delicate minute crowded
striae, which at the centre are oblique, at the
shorter end curved and flexuous, at the pro-
duced end straight, and which meeting the
oblique striae of the centre form with them
angles ; the hinge which is towards the poste-
rior side, has two small teeth in one valve, and
one in the other, with strong laminated lateral
teeth ; flesh colour both within and without,
length about three quarters of an inch, breadth
rather more.
* Carnaria is derived from the latin carne, flesh, this
species being so called from their flesh colour.
CARDIUM— COCKLE. 161
Genus.— CAHVIUM*— (Plural, Cardia.)
Generic Character. Shell bivalve, equivalve,
nearly equilateral ; shape, convex, the contour of
many of the species when viewed with either of
the slopes in front, exhibits the form of a heart ;
surface either ribbed, striated, or furrowed lon-
gitudinally ; margins toothed, the ribs or fur-
rows of the two valves being so arranged as to
alternate at the margins, and to fit closely into
each other ; the hinge has four teeth in each
valve, the two central are oblique, approxima-
ting, and articulating with the teeth of the other
valve, two lateral teeth remote ; the beaks are
turned inwards ; the unbones are turgid ; the
ligament is external.
OBSERVATIONS ON THE SHELL AND ITS
INHABITANT.
The Cardium is readily distinguished from
the shells of other genera by the peculiarity of
its teeth and its cordate form ; its ribs or striae
also are invariably longitudinal. The mollusks
of this genus are furnished with two short un-
equal tubes, fringed with hairs at their ex-
tremities ; they have a strong muscular foot
which enables them to move with great rapidity.
* Plate VIII. figures 1, 2.
M
162 BIVALVES.
They live buried under the sand, but select a
spot within reach of the waves, as they require
frequent supplies of water, and to obtain it, are
continually protruding their tubes. Many of
the species afford nutriment to the poorer classes.
The name is derived from the Greek Kafita
(cardia) a heart.
CARDIUM Edule*
COMMON COCKLE.
Specific Character. Shell convex, sometimes
produced at the posterior end, with about
twenty-six longitudinal ribs and transverse
wrinkled striae, which in old specimens appear
somewhat imbricated ; colour whitish, or pale
ferruginous ; about an inch and a quarter long,
and an inch and a half broad.
This species is very common in most of our
inlets and bays near the mouth of rivers, where
the shore is sandy. They are found buried
three or four inches under the surface. The
moliusks when boiled, afford a wholesome
nourishment.
CARDIUM Tubereulatum.^
TUBERCULATED COCKLE.
Specific Character. Shell somewhat orbicular,
ponderous, slightly truncated at the anterior
* Edule, eatable, from the Latin ed ere, to eat.
f Plate VIII. fig. 2.
MACTRA— KNEADING-TROUGH. 63
side, with twenty-one ribs, the anterior ones
having sharp tubercles, and the posterior thick
transverse scaly plates ; colour, pale brown, with
darker transverse bands ; breadth not quite
four inches, and rather exceeding the length.
This shell, and the Cardium Echinatum,
which it greatly resembles, are found in abund-
ance on the Paignton sands in Torbay, where at
low tide they may be observed with their
fringed tubes just appearing above the surface
of the sea. The neighbouring cottagers collect
them in baskets, and after cleansing them in
cold spring water, fry the mollusks in a batter
made of crumbs of bread, which make a whole-
some and savoury dish ; they call them Red
Noses.
Genus.— MACTRA.*— (Plural, Mactrce.)
KNEADING-TROUGH.
Generic Character. Shell bivalve, equivalve,
inequilateral, sometimes gaping ; shape generally
nearly triangular ; hinge with the cardinal tooth
complicated,! and an adjacent cavity filled
* Plate VIII. figures 3, 4.
f Complicated, folded together, from the Latin con, with,
together, and plica re, to fold.
M 2
164 BIVALVES.
by the ligament which is internal, the lateral
teeth laminar, double in one valve, inserted.
OBSERVATIONS ON THE SHELL AND ITS
INHABITANT.
The shells of this genus are clearly marked
by their angular central tooth, and internal
ligament. They vary little in form or colour-
ing, and do not display much beauty; they
are usually semipellucid, and of a thin delicate
appearance; the surface is seldom diversified
by inequalities. The prevailing colour is blueish,
or yellowish white, sometimes radiated. The
animal has not the power of progressive motion,
but by the assistance of a small compressed
muscular foot, it is enabled to change its posi-
tion, a little : this organ projects at one end of
the shell, and at the other are two tubes formed
by the mantle. The name Mactra is derived
from the Greek paKrpa, (mactra) a kneading-
trough.
MACTRA Stultorum*
SIMPLETON'S KNEADING-TROUGH.
Specific Character. Shell subtriangular, con-
vex, thin, brittle, semipellucid ; colour white
* Plate VIII. fig. 4.
MACTRA— KNEADING-TROUGH. 165
grey, or pale brown, radiate more or less from the
hinge with paler stripes, sometimes of a purplish
hue about the beaks, and inside of the valves; the
umbones are gibbous; length an inch and a
quarter, the breadth one and three quarters.
Common on most sandy coasts.
MACTRA Compressa or Piperata.
PEPPER MACTRA.
Specific Character. Shell subtriangular,
roundish, compressed, thin, semipellucid, finely
striated ; umbones small, central ; hinge without
lateral teeth, cartilage cavity large, triangular,
cardinal teeth small, a single one locking into a
bifid one in the opposite valve ; of a yellowish,
reddish, or white colour often stained with black
occasioned by the mud in which it resides ;
about an inch and quarter long, and an inch
and half broad.
This is one of the most beautiful of the Bri-
tish species of Mactra ; it is chiefly found at the
mouth of inlets or rivers, not remote from fresh
water ; for though it always seeks a spot within
reach of the flux of the tide, it delights in situa-
tions over which fresh water occasionally flows.
It lives in the mud, buried about five or six inches
deep. The animal has two slender tubes of a
yellowish colour placed near together at the an~
terior end of the shell : one about three inches
166 BIVALVES.
long it protudes in search of its food, which
consists of insects ; these may be seen passing up
its transparent siphon, drawn in with the current
of water it is continually receiving, and which
it discharges at the shorter tube, retaining only
the nutritious matter it contained.
Genus— DONAX *— (Plural, Donaces.}
WEDGE SHELL.
Generic Character. Shell bivalve, equivalve,
inequilateral ; the form like a wedge, broad,
thick, and obtuse at the anterior end, and gra-
dually narrowing and lessening at the posterior ;
the margin is often crenulate, and usually
gaping ; the hinge has two central teeth in each
valve, and one remote lateral one ; the ligament
is external.
OBSERVATIONS ON THE SHELL AND ITS
INHABITANT.
The wedge-like form of the donaces easily
distinguishes them. The derivation of the name
from Sovaf , (donax) an arrow, may have been
* Plate VIII. figures 5, 6.
DONAX— WEDGE SHELL. 167
adopted either as indicative of the sagittate
form, or of the rapidity with which, in conse-
quence of its peculiar shape, the animal can
dart into the sand, whenever danger threatens.
One species (Donax Irus) perforates the hardest
limestone, but by what means it effects a lodg-
ment in such a substance, has not been ascer-
tained ; pieces of stone are often thrown ashore
on the Devonshire coast filled with these shells
fitting into the apertures which they have pierced.
The shells of this genus are generally of a fine
rich purple colour, sometimes marked with rays
of purple on a white ground. Many of the
species are of a yellow olive hue. The animal
has two long slender tubes not joined together,
and a lamellar foot. The Donaces are marine
littoral shells.
DONAX Denticulate. \ ,.,
TOOTHED DONAX.
Specific Character. Shell strong, thick, ovate,
wedge-shaped, with longitudinal striae, the in-
terstices punctured ; * anterior slope rough, with
transverse striae, and elevated in the middle in
a kind of keel ; white or lead colour, usually
with a few purple rays proceeding from the
urabones, inside purple ; very concave under
* Punctured, pricked or marked with small dots, from the
Latin punctww, a point or dot. . v»" -
168 BIVALVES.
the umbones; margin denticulated; about half
an inch long and nearly an inch broad.
This is described as a British species, but it
is .rarely found on our coasts. It inhabits the
West Indies, Africa, and the Mediterranean.
Genus— VENUS— (Plural, Veneres.)
VENUS.
Generic Character. Shell bivalve, equivalve,
inequilateral, closed ; shape ovate, suborbicular,
or subcordate ; both the area and areola are well
defined, the area is generally flattened, and the
areola has often the impression of a heart ; the
hinge has three approximate cardinal teeth,
the middle one is longitudinal , the others diverg-
ing, there is a lateral tooth in a few species ;
the beaks are turned towards the areola, that is
from the ligament.
OBSERVATIONS ON THE SHELL AND ITS
INHABITANT.
The shells of this genus, preeminent for the
elegance of their form, and the beauty of their
colouring, have in consequence, been designated
by the name of the fabulous goddess of beauty.
The three approximate teeth, and the inclination.
* Plate VIII. figures 7, 8.
VENUS— VENUS. 169
of the beaks towards the areola, at once deter-
mine a shell to be a Venus, but these marks are
sometimes wanting ; in a few species there are
four cardinal teeth in each valve, and this is the
distinguishing mark of the genus separated from
this, under the name Cytherea. Those Ve-
neres which have only two teeth in each valve,
belong to the modern genus Crassina.
The Venus is diffused over every part of the
world, and in many countries affords to animals
and birds a nutritious food. It is curious to
observe the contrivances by which the sea-fowl
endeavour to procure the mollusks of this and
other genera ; they have been seen to take
advantage of a moment, when the shell is
open, to drop a pebble between its valves,
which being thus prevented from closing, the in-
mate is left exposed to their attacks. Sometimes
when they find the shell so hard as to resist all
their efforts to break it with their beaks, they
ascend to some lofty eminence, and letting it
drop upon rough or craggy rocks, it is crushed in
the fall, and the animal thus becomes their prey.
The mollusk of the Venus has two siphons
formed by the mantle, and a lamellar foot.
VENUS Mercenaria.
MONEY VENUS.
Specific Character. Shell ponderous, ob-
170 BIVALVES.
liquely heart-shaped, slightly striated trans-
versely ; posterior depression cordiform ; inner
margin crenated ; the outside is greyish or
brownish, the inside is white, with a violet-
coloured spot at the anterior side; the length
is about two inches and three-quarters, the
breadth about three inches and a half.
The Indians of North America cut these
shells into beads, some white and some black ;
of these they form their wampum, or treaty-
belts, which are symbolical of friendship. They
also string them together and use them for
money. The females cover the shoes they wear
in dancing with these shells, which in their
movements being struck together produce a
sound resembling the tinkling of the bells used
by the Israelitish women, and mentioned in
Isa. iii. 16.
VENUS Dysera*
RIBBED VENUS.
Specific Character. Shell triangular, convex,
heart-shaped, marked with distinct concentric
raised ridges, which are closely cancellated ; f
the longitudinal striae are also crossed by fine
* Plate VIII. figure 8.
"T" Cancellated, crossed like the bars of a window, from
the Latin cancelli, lattice.
SPONDYLUS— THORNY OYSTER. Ml
transverse lines ; margin crenated ; colour grey,
or ivory white, variously marked with chesnut
brown spots, the area and areola are of the same
colour as the spots ; diameter about an inch.
Found on the shores of Germany, America,
and the East Indies.
Genus - SPONDYLUS.*— (Plural, Spondylt. )
THORNY OYSTER.
Generic Character. Shell bivalve,inequivalve,
inequilateral, fixed, strong, solid ; surface coarse
and rough, with either lamellar or subulate
spines ; the hinge has two strong recurved teeth
in each valve, with an intermediate sinus for the
ligament; the lower valve is convex, and is
produced at the apex into a projecting beak
which appears as if it had been sliced off by a
sharp instrument, presenting a triangular flattened
surface, having a groove which receives the
decaying part of the ligament. The shell is
often eared.
OBSERVATIONS ON THE SHELL AND ITS
INHABITANT.
The shells of this genus are remarkable, not
* Plate VIII. figures 9, 10.
172 BIVALVES.
only for the brilliancy of colouring, which most
of them display, and for the singularity of their
external form, but also for the clearness and
precision of the characters which distinguish
them from the shells of other genera. The
roughness and irregularity of their appearance,
their two strong incurved teeth, with the inter-
mediate sinus for the ligament, are their discri-
minative generic marks. The genus contains
only three species, one of which has not the
flattened beak and internal ligament, and its
shells are remarkable for being plaited longi-
tudinally like a fan half opened ; they have been
separated by modern conchologists from the
Spondylus under the significant name of
Plicatula.* The Spondyli adhere to rocks, co-
rals, and other marine substances, at considerable
depths in the sea, they are separated from them
with very great difficulty, they are found often
in groups forming large masses. The animal
has the edge of its mantle fringed with short
tentacular filaments ; it has a small radiated
foot. From a supposed resemblance of the
Spondylus to the oyster it has been called the
thorny Oyster ; its scientific name is derived
from the Greek <nrov$vXos (spondulos) the head
of an artichoke.
* Plicatula, a little fold, from plica a fold. Plate VIII.
figure 10.
CHAMA— CLAM OR CLAMP. 173
SPONDYLUS Gcedaropus*
THORNY OYSTER.
Specific Character. Shell slightly curved,
spinous, varies greatly in colour, size, and the
form of the spines, the latter are generally lam-
inated or tongueshaped, sometimes foliated ; the
colour varies from saffron, to orange and scarlet ;
the size is about two inches in diameter.
It is found adhering to rocks in the Mediter-
ranean.
Genus— CHAMA.f (Plural, Chama.)
CLAM OR CLAMP.
Generic Character. Shell bivalve, solid exte-
rior usually coarse ; hinge has a gibbous callo-
sity inserted obliquely into a corresponding
sinus in the opposite valve ; this callosity or
tooth is either simple or crenated ; beaks re-
curved; form various.
OBSERVATIONS ON THE SHELL AND ITS
INHABITANT.
This genus, as it stands in the Linnaean classi-
fication, contains twenty-six species, but some
* Plate VIII. figure 9. t Plate IX, figures 1, 2, 3.
174 BIVALVES.
of these are remarkably dissimilar in their ap-
pearance. It includes regular, and irregular,
equivalve and inequivalve shells, also some that
are attached to marine substances, and others
that are free. The callous ridge at the hinge is
the most decided character of the genus. The
name is derived from wpy (chem6) a gaping,
and is applicable to many of the species ; it is
probable that all those which have an opening
at the margin, possess a byssus, by which they
are fastened to rugged substances. This genus
affords subject of amazement in the uncommon
size to which some of its species attain. The
Giant Clam (Chama Gigas) is a specimen of
unusual magnitude in a shell : it is indeed the
largest of all testaceous productions. One of
these shells described by Linnaeus, weighed four
hundred and ninety-eight pounds; and he says
that its inhabitant furnished one hundred and
twenty men with a day's food. So great were
the weight of the shell and the strength of the
muscles, that by suddenly closing its valves, it
cut asunder a cable. Another specimen brought
from Sumatra, is preserved in Arno's Vale, in
Ireland, its weight is five hundred and seven
pounds; the largest valve measured four feet
six inches in length, and two feet five inches and
a half in breadth. A specimen of this extraox-
.dinary species, forms a very elegant baptismal
font in the church of St. Sulpice, in Paris, it
was presented by the Venetians to Francis I.
Large pearls are occasionally found in the
CHAMA— CLAM OR CLAMP. 175
Chamae ; one exhibited at Sir Joseph Banks',
was valued at between two and three hundred
pounds. The colour of Chama Gigas, is a
dingy white : the ihinge is furnished with a car-
tilage of a dull colour, which when cut and
polished, is as beautifully iridescent as Opal.
CHAMA Cor*
HEART CLAM.
Specific Character. Shell equivalve, globose,
heart-shaped when viewed from the posterior
side; thick, strong, smooth, or only slightly
striated transversely : umbones large and promi-
nent, apices involute, and turned to one side :
colour pale yellowish brown, covered with a .
darker epidermis, decorticated at the umbones.
Shell about three inches long, and two and three
quarters broad.
This shell has but very rarely been found in
the British seas ; it is much prized on account
of the singular and graceful beauty of its form.
It belongs to the new genus Isocardia.
CHAMA Hippopus. *
BEAR'S PAW CLAM.
Specific Character. Shell equivalve, inequi-
lateral, thick, heavy, longitudinally ribbed and
* Plate IX. figure 3. t Plate IX. figure 2.
176 BIVALVES.
muricated ; * posterior slope heart-shaped,
closed ; margin in front deeply sinuous ; the co-
lour is white or yellowish, with scattered reddish
or purplish spots ; commonly about two inches
long, and three inches and a quarter inside, but
it sometimes occurs double this size.
It inhabits the East Indian ocean. •
Genus— ARC A.f (Plural, Areas.)
Generic Character. Shell bivalve, equivalve,
inequilateral ; form various, often oblong, some-
times orvicular ; hinge with numerous small
sharp teeth in each valve, alternately inserted
between each other, arranged sometimes in a
straight, sometimes in a curved line ; beaks ge-
nerally remote ; ligament external.
OBSERVATIONS ON THE SHELL AND ITS
INHABITANT.
The shells of this genus are very readily
known, by their numerous small teeth. Some
of the species attach themselves to rocks by a
kind of byssus : these have always the shell more
or less gaping ; but the greater part of the Arks
live buried in the sand at a short distance from
* Muricated, having little pointed knots, from the Latin
murex, the sharp point of a rock.
f Plate IX. figures 4, 5,6.
ARCA— ARK. 177
the shore ; all are marine. The mollusk has
no external siphons, it has a kind of compressed
peduncle, terminated by tendinous filaments,
which are affixed to rocks. The shells of this
genus which have the teeth arranged in a curved
line, have been formed into a new genus called
Pectunculus; * their form is orbicular, and
they are not attached to rocks,
ARCA
NOAH'S ARK.
Specific Character. Shell oblong, roundish at
one end, elongated at the other, narrow, and
inclining to angular ; beaks lateral, remote from
each other, the apices incurved with a broad
smooth space between them ; teeth in a straight
line ; surface strongly striated longitudinally,
and crossed with transverse lines ; margins sinu-
ous and somewhat gaping , of a pale rufous
colour, with dark oblique bands ; the broad
flat space between the apices has a few distant
grooves radiating from the umbones ; length
about an inch, breadth two.
This singular shell much resembles the hulk
of a ship ; the flattened area and areola may be
considered as the deck, the pointed end the prow,
the gibbous and rounded end the stern, and the
acute edge of the united margins has the appear-.
* Plate IX. figure 5. f Plate IX. figure 6.
N
178 BIVALVES.
ance of the keel. The form of the shell
suggested the name of Noah's Ark, and from
this fancied resemblance in one species to the
ark, the genus owes its designation.
This shell is affixed to rocks by a very strong
tendinous substance, there is an open space in the
front of the valves, through which it issues.
It inhabits the Mediterranean, Indian ocean,
West Indies, and Britain.
ARCA Undata*
LETTERED ARK.
Specific Character. Shell suborbicular, nearly
smooth, with faint reticulated f striae ; margin
crenated ; teeth in a curved line ; colour white,
variegated with yellowish red spots, in undu-
lated transverse bands.
Inhabits the West Indies, and shores of Italy.
It belongs to the modern genus Pectunculus.
* Plate IX. figure 5.
f Reticulated, having the appearance of net work, from
the latin reticulum, a small net.
OSTREA— OYSTER, SCALLOP, 179
Genus— OSTREA.*— (PZwraZ, Ostrecs.)
OYSTER, SCALLOP, OR PECTEN.
Generic Character. Shell bivalve, generally
inequi valve, inequilateral, more or less eared ;
hinge without teeth, having an ovate sinus, in
which is fixed an elastic cartilage, and generally
lateral transverse grooves.
OBSERVATIONS ON THE SHELL AND ITS
INHABITANT.
This genus contains shells very different in
their general appearance, but united by the
peculiarity in the hinge, which is toothless, and
has an elastic cartilage inserted into a sinus. It
may be divided into two families, the Pecten or
Scallop, and the Oyster,* which are separated
by very marked distinctions.
The Pecten is of a regular orbicular form,
and eared ; its surface is adorned with diver-
gent ribs, which proceed from the apices to
the circumference, where they terminate in a
scalloped margin. The shells of this division
usually display brilliant colours.
The second division contains the species more
or less resembling the common oyster; these
* Plate IX. figures 7, 8:
N 2
180 BIVALVES.
shells are irregular in their form, have a rugged
and laminated exterior, with one valve more con-
cave than the other, are generally without ears,
and their colour is grey or black.
The Pectens are described as possessing asto-
nishing powers of locomotion, considering the
inferiority of their organization ; but dexterity
and ingenuity frequently compensate for natural
deficiency. They have the power of progressive
motion, both on land and in the water. When
the animal happens to be left on the shore by
the retiring tide, it opens its valves to their
full extent, and closing them with great mus-
cular power, is thrown forward five or six
inches by a sudden leap. In this manner it
reaches the sea ; should the weather be calm, it
raises one of its valves, which catching the breeze,
acts as a kind of sail, while the other resting on
the surface, supports the floating animal ; when
danger threatens, the shell is closed, and sinks
securely to the bottom of the sea. Many of the
Pectens possess the power of forming threads, by
which they anchor themselves to floating timber,
and by this means find protection when the sea
is agitated by storms and tempests. These
varied means of escaping danger are no doubt
afforded as a necessary protection against their
numerous enemies. The pilgrims who in former
days visited Jerusalem, to pay their devotions
at the holy sepulchre, on their return wore
these shells in their caps as trophies of their
achievement in crossing the sea for this sacred
OSTREA— OYSTER, SCALLOP. 181
purpose ; and in commemoration of this super-
stitious act of devotion, it was often granted them
to have Pectens engraved in their coats of arms,
that a record of their religious zeal might be
handed down to posterity.
The shells of the second division differ from
the Pectens as much in their habits as in their
appearance. They are reputed to be some
of the most sluggish of animals, and to have very
limited powers and faculties ; but whilst we
cannot fail to observe this destitution, we trace
the goodness of the Creator, who has placed them
in situations not exposed to danger, and bestowed
upon them an organization that requires but
little to satisfy it. The only nourishment they
need is brought to them by the ever-flowing
waves, and they scarcely exhibit any symptom
o life, but that of opening their valves to
receive the water, and then closing them for
security. Firmly attached to the rocks, and
enclosed within their strong testaceous dwelling,
they are protected against surrounding dangers.
They sometimes effect a change in their posi-
tion by a curious contrivance ; they manage to
bolster up one valve in the sand or mud, and
having thus fixed themselves erect, they open
their shells, and the flowing or reflux of the tide
forces them over by the pressure of the water.
The animal has neither siphon nor foot.
182 BIVALVES.
OSTREA Edulis.
COMMON OYSTER.
Specific Character. Shell more or less orbicu-
lar, inclining to oval, but subject to much vari-
ation in form and size, imbricated with scaly
laminae ; upper valve small and flattened, the
other convex ; inside pearly white, outside dull
brown.
Oysters are generally found with their lower
valves fixed to rocks or loose stones, and fre-
quently to one another. Most of our rocky
coasts abound with these shells, but Essex and
Suffolk chiefly are celebrated for them. They
are dredged up by a kind of net, with an iron
scraper at the mouth, and are immediately
stowed in pits formed for the purpose in the
salt marshes, which are overflowed only at spring
tide, and from which sluices let the salt water
escape, retaining a depth of about eighteen feet.
The water being stagnant, in warm weather it
becomes green, and in a few days the oysters
acquire the same tinge ; they are then held in
great estimation in the market, but they do not
attain their greatest perfection under six or eight
weeks.
Oysters are not considered fit for the table till
they are about a year and half old, and the fish-
ermen know their age by the increase in the size
of the distance which separate the circles of
laminae in the convex valve. When young
OSTREA— OYSTER, SCALLOP. 183
shells happen to be taken, they are always
rejected and cast back into the sea. Great
Britain has for many ages been noted for its
oysters, which in former times were sent as a
peculiar delicacy to the epicures of Rome.
OSTREA Malleus*
HAMMER OYSTER.
Specific Character. Shell flexuous, elongated
at the base, often produced into two lobes giving
it somewhat the form of a hammer, from whence
it derives its name ; outside imbricated with
scaly laminae ; the colour generally dark grey
or blackish ; inside very glossy, pearly, and
tinged with blue ; it is about five or six inches
long, and four or five across from the extremities
of the two lateral lobes.
This shell is much prized on account of its
very singular appearance. It is found in the
Indian Ocean : its animal forms a byssus which
passes through a small opening in the shell near
the beaks. It now is arranged in the genus
Malleus.
PECTEN Maximus.
GREAT SCALLOP.
Specific Character. Shell inequivalve with
* Plate IX. figure 8. " .
184 BIVALVES.
equal auricles ; upper valve flattish, depressed
near the hinge, lower valve convex ; the sur-
face has about fourteen rounded ribs, is longi-
tudinally grooved, and very finely striated trans-
versely ; the lower valve is white, tinged with
red ; upper valve reddish brown or spotted with
pink and brown ; inside white with a reddish
brown margin ; length five inches, breadth six.
This shell is not uncommon on some of our
coasts, particularly at the mouth of large rivers ;
it is frequently sold for the use of the table, and
is much esteemed as a nutritious diet. It is
asserted by fishermen, that they are taken in the
greatest quantities after a fall of snow. This
was the species worn by the Pilgrims who visited
the Holy Land.
Genus-ANOMIA.* (Plural, Anamia.)
ANOMIA, OR ANTIQUE LAMP.
Generic Character. Shell bivalve, inequivalve,
form suborbicular, one valve flattened, and often
perforated in the disk, the other more concave,,
and sometimes having its beak produced and
curved over the hinge, and perforated at the
apex ; hinge toothless, having a linear projection
which is united under the beak to the opposite
valve by a strong ligament.
* Plate IX. figure 9 ; Plate X. figure 1.
ANOMIA— ANTIQUE LAMP. 185
OBSERVATIONS ON THE SHELL AND ITS
* INHABITANT.
This genus contains a variety of shells mate-
rially differing in their appearance. The perfor-
ation in one of the valves for the emission of a
ligament, by which the animal adheres to marine
substances, is, perhaps, the most general, though
not an invariable characteristic.
The Anomiae are now arranged in two prin-
cipal groups, very clearly distinguished from
each other. The shells of one division retain the
name of Anomia, and very much resemble a
small oyster in their appearance ; like them they
are fixed and stationary, living and perishing on
the spot where the egg was first deposited.
They are attached by means of a bony appen-
dage, having a dilated base ; this is in fact only
a prolongation of the adductor muscle of the
animal ossified at its outer extremity. When
the mollusk contracts the muscle, the dilated
portion is drawn over the perforation of the
flattened valve and covlrs it, acting as an oper-
culum. So firmly are the shells fixed by this
organ, that they cannot be removed from their
retreat, without destructive violence, the liga-
ment and operculum being left on the rock to
which they were cemented. The form of the
Anomia, like that of all stationary shells, is very
irregular, being usually modified by the sub-
stances to which it adheres. The prevailing co-
186 BIVALVES.
lour of this genus is a dingy yellow, or dusky
white; the shells are generally thin, fragile,
delicate, and would be ill-fitted to contend with
the dangers of their dwelling in the boisterous
ocean, had not He who placed them amidst its
perils, exercised his compensatory providence,
and anchored them securely in its depths. The
animal belonging to the shells, is very similar to
the oyster.
The other family of this genus now bears the
name of Terebratula. The shells which it con-
tains, are distinguished by the graceful elegance
of their form, which resembles a Grecian lamp,
and from hence they are called the Antique
Lamps. The concave valve of the Terebratula
has its beak produced, curved over the other
valve, and perforated at the apex ; the smaller
valve is furnished with two slender shelly pro-
cesses, which are sometimes short, simple, and
recurved ; sometimes long, branching and cross-
ing each other ; their use is not ascertained, but
it is supposed that they are supports for the ani-
mal. The Terebratulae inhabit the depths of
the ocean ; they are parasitical, and are attached
to various submarine substances by a tough short
stalk which differs from the ligament of the
Anomia in being formed of numerous closely
united fibres, separating a little at the end, by
which they are fixed. The mollusk which in-
habits this shell is remarkable for two long
fringed arms, rolled up in a spiral form within
the shell when at rest, but which it protrudes
when hunger prompts it to seek for food.
ANOMIA— ANTIQUE LAMP. 187
ANOMIA EpUppium.*
WRINKLED ANOMIA.
Specific Character. Shell suborbicular, irre-
gular, wrinkled, sinuous at the margin ; inside
pearly and iridescent; colour yellow, reddish or
white : varies from two to three inches in
diameter.
This shell belongs to the division still bearing
the name of Anomia. It adheres to other
bodies, and particularly oysters, and receives
the impression of the substances to which it is
affixed, its form being modelled by the circum-
stances under which it adds to its size. Some
specimens have been taken from the Pecten
Maxim us exhibiting clearly the impression of
its ribs.
ANOMIA Psittacea. f
PARROT BEAK ANOMIA.
Specific Character. Shell oval, horny, pel-
lucid; the beak much produced, curved, and
perforated, the hole sub triangular ; margin sinu-
ated, entire; surface finely striated longitudi-
nally ; colour is blackish, or greenish brown ;
length about three quarters of an inch, exceeding
the breadth.
This shell belongs to the Terebratulae : it in-
habits the Indian Sea, and Greenland.
* Plate X. figure 1. t Plate IX. figure 10.
188 BIVALVES.
Genus— MYTILUS.* (Plural, Mytili.)
MUSCLE.
Generic Character. Shell bivalve, rough,
generally affixed by a byssus to marine sub-
stances ; shape generally a long oval, sometimes
lobed, sometimes elongated at the beaks ; hinge
mostly without teeth, marked by a furrow or
by a subulate line, which is crenated in some of
the species.
OBSERVATIONS ON THE SHELL AND ITS
INHABITANT.
Though all the Mytili are not inseparably
attached to other subtances, all are by some
means rendered stationary ; the silky filaments
produced by some of the species are entwined
in the coralines and stones at the bottom of the
sea, and securely anchor the group of muscles
found there. Others of the species perforate
rocks or even large shells, and form for them-
selves at once their residence and grave. The
Mytili which have their beaks nearly terminal
and pointed, and are of a dark colour, much
resemble a mouse, and from the circumstance
of a few species being like this animal, the
genus has received its name, which is derived
* Plate X. figure 2.
MYTILUS— MUSCLE. 189
from {AtmXo? (mutilos) the diminutive of pv$
(mus) a mouse. Some of the species have their
base elongated with lobes on each side, and bear
a resemblance to a bird in full flight.* The
name Mytilus is now confined to the shells
whose beaks are terminal.
MYTILUS Edulis. f
COMMON MUSCLE.
Specific Character. Shell oval, pointed at the
beaks ; sides much sloped, flattish at the an-
terior, and rather angular and carinate at the
posterior end ; hinge terminal ; beneath the
margin are several tooth-like crenulations ; colour
often of a rich blue when deprived of its epider-
mis which is brown; inside blue about the
margin, and whitish in the middle, length from
two to three inches, and about half as broad.
This shell is the most common of all the
British species, and is found in large beds,
attached by a byssus. The mollusks have a
tongue-shaped muscular foot, capable of great
powers of elongation and contraction ; with this
instrument they are able to effect a progressive
motion. Forming a furrow in the sand, and
placing their shell erect, they stretch out the
foot, which being rather viscid, adheres to the
ground, and when an effort is made to contract it,
* Plate X. figure 3. t Plate X. figure 2.
190 • BIVALVES.
the shell is drawn along the groove. Thus
alternately extending and contracting this mus-
cular instrument, the Mytilus contrives to creep
to a convenient situation for anchorage, and by
means of this same foot it then forms a coarse
byssus, which fixes it to the chosen spot. Often
towards the end of autumn a little crab is found
sheltering itself within the valves of the muscle.
This little creature is called the Pisum, or Pea
Crab : it is supposed so have been placed
in the shell of the Mytilus and other Bivalves,
to assist by its sagacity, the more limited powers
of its host, whom it repays for a safe retreat,
by going in search of provender, and sharing it
with him.
MYTILUS Margaritiferus.
PEARL-BEARING MUSCLE.
Specific Character. Shell suborbicular, com-
pressed, the margin rounded, except on the
hinge side where it is straight and transverse ;
surface imbricated with transverse membra-
naceous scales, having the laminae toothed in
rays ; colour commonly greenish or pale ches-
nut, inside pearly and iridescent ; the full
grown shells are sometimes ten or twelve inches
long and rather less in breadth : they are thick,
and ponderous, but young specimens are thin,
brittle, and slightly eared.
* Plate X. figure 3.
MYTILUS— MUSCLE. 191
This species now forming the genus Melagrina,
is much celebrated for producing pearls. They
are thought to be occasioned by a disease in the
Mollusk, and to be produced by a partial
secretion of the substance of which it forms the
inner coating of its shell ; it is arranged in the
pearl in concentric layers. Acids, have the
same effect upon pearls as upon other carbonates
of lime, and Cleopatra is said to have dissolved in
vinegar one of great value in order to display
her magnificence by this costly draught. The
pearl fishery is a very dangerous employment ;
it is principally carried on in the Persian Gulph
and the neighbourhood of Ceylon ; the season
for the fishery lasts about a fortnight. Numer-
ous boats are dispatched to the station where it
is carried on, each containing twenty men, ten
of whom are employed in rowing and assisting
the divers. They descend alternately in parties
of five, and thus time is afforded for all to
recover themselves after their violent exertion.
The diver has a rope attached under his arms,
the end of which is given to the men in the
boat ; round his neck is slung a net, distended
at the opening by a hoop. Closing his nostrils,
he commits himself to the sea, with a perforated
stone of ten or twenty pounds weight affixed to
his foot, to accelerate his descent. He sinks
generally a depth of twenty or thirty yards;
then quickly proceeding to his work, he tears
the muscles from their bed, fills his net, makes
a signal and is drawn up again to the surface.
192 BIVALVES.
Many and great are the dangers attendant on
this employment. The greedy shark often
marks the diver for his prey, his only chance of
safety under such circumstances, is by muddy-
ing the water, and so eluding the animal's obser-
vation. A large flat fish also sometimes attacks
him, and keeps him under water till he is drowned.
When drawn up in safety to his vessel, he often
in consequence of his exertion discharges blood
from his mouth and nostrils. The divers rest
and labour alternately, during periods of about
ten minutes.
Genus— PINNA— (Plural, Pinna.)
Generic Character. Shell bivalve, equivalve,
fragile, thin, gaping at one end, and furnished
with a byssus ; shape subtriangular, narrow at
the beaks, and expanding to a considerable
breadth at the opposite extremity ; hinge with-
out teeth ; valves united by a long external
ligament.
* Plate X. figure 3.
1NJJA-
—SEA WING. 193
OBSERVATIONS ON THE SHELL AND ITS
INHABITANT.
The Pinna seems to form the connecting link
between the univalves and bivalves, for though
it is composed of two valves, yet it is incapable
of moving on its hinge. It is generally found at a
short distance from the shore, fixed in the mud
at its smaller end, and standing erect. The ani-
mal forms abyssus, the fibres of which are ag-
glutinated, to the sand, gravel, roots of marine
plants, broken shells, or any matter within its
reach. The byssus of the Pinna is much more
fine and delicate than that of the muscle ; the
filaments are long, silky, and of a bright lustre ;
the natural colour is of a rich golden brown, but
it readily receives any tint. The animal pos-
sesses a kind of tubular instrument, furnished
with a gland which secretes a glutinous sub-
stance : by means of a slight pressure, a drop
of this liquid is deposited on the spot, to which
the byssus is to be attached ; by the retraction
of the foot, a silken filament is drawn out, and
this operation being repeated some thousands of
times, a beautiful tuft of silky fibres, is pro-
duced. The Pinnae are much sought after on
the coasts of Sardinia and Corsica for the sake
of the byssus; they are fished up with an instru-
ment which consists of two semicircular bars of
iron fastened together at each end, but three
o
194 BIVALVE|A
inches distant from each other at the centre. At
one end is a hollow handle, in which a pole is
fixed, at the other is a ring, to which a cord is
fastened. When a Pinna is discovered, the iron
is let down slowly over the shell, which is then
twisted round and drawn out. When a suffi-
cient number have been caught, the silk is cut
off, and after being twice soaked in tepid water,
and once in soap and water, is spread out to dry
in some cool and shady place. Whilst it is yet
moist, it is again softly rubbed and separated
with the hand, and then spread out again. When
thoroughly freed from moisture," it is drawn
through a comb with the teeth wide apart, and
afterwards through a similar instrument, with
finer and closer teeth. The more common silk
is thus prepared, but that which is destined for
finer works, is afterwards drawn through closer
iron combs or cards. It is spun, two or three of
the threads being mixed with one of real silk,
and then knitted into gloves, stockings, and
even whole garments. When the piece is knitted,
it is washed in clean water mixed with lemon
juice, gently beaten between the hands, and
smoothed with a warm iron. The shells of the
Pinna are often ornamented with elevated longi-
tudinal ribs, crossed by striae, sometimes ter-
minated by imbricated arched scales, or pro-
minent tubular spines. Some of the young
shells of this genus are less than an inch in
length, whilst the'adults often exceed three feeti
The Pinna as well as the Muscle, was much
PINNA— SEA WING. 195
celebrated by the ancients ; they supposed it to
harbour within its shell a small crustaceous
animal, a kind of shrimp, which was said to be
of the greatest use to its companion, by warning
it of the vicinity of the prey upon which it
subsists, or of the approach of its great enemy
the Sepia. Many stories are related of the
amiable habits of this pair, and of the mutual
services they render each other. The truth of
these accounts are much confirmed by small ani-
mals of the crustaceous tribe being continually
found in the shells of the Pinna and Muscle.
The ancients have celebrated these histories, by
making them the subject of poetry ; the follow-
ing verses are translated from a latin author, and
are very descriptive of the habits of the Pinnse.
In clouded deeps below the Pinna hides,
And through the silent path obscurely glides ;
A stupid wretch, and void of thoughtful care,
He forms no bait, nor lays the tempting snare ;
But the dull sluggard boasts a crab his friend,
Whose busy eyes the coming prey attend.
One room contains them, and the partners dwell
Beneath the convex of one sloping shell ;
Deep in the watery vast the comrades rove,
And mutual interests binds their constant love.
That wiser friend the lucky juncture tells,
When in the circuit of the gaping shells
Fish, wandering, enter ; then th* bearded guide,
Warns the dull mate, and pricks his tender side ;
He knows the hint, nor at the treatment grieves,
But hugs the advantage, and the pain forgives :
His closing shells the Pinna sudden joins,
And 'twixt the pressing sides his prey confines.
Thus fed by mutual aid the friendly pair
Divide their gains, and all their plunder share.
O 2
196 MVALVES.
The name Pinna, which is sometimes spelled
with one n, is supposed to be derived from nuo<;
(pinos) the dirt or mud ; but the name given it
by British conchologists would lead us to take
its derivation from the Latin, pinna, a large
feather.
PINNA Pectinate.*
SPINY SEA WING.
Specific Character. Shell triangular, oblong,
with about eleven longitudinal ribs, having con-
cave spines, which increase in size as they
approach the broadest end ; the other side desti-
tute of ribs, but obliquely striated ; shell thin,
pellucid, brittle, of a light brown colour, darker
towards the beaks ; inside of a pearly hue ;
breadth three inches at the gaping end, which
is slightly rounded ; length six inches and a
half. This shell inhabits India ; it has also been
found on the coasts of Dorset and Sussex.
QUESTIONS ON THE BIVALVE
SHELLS.
1. Describe the part of a Bivalve shell which
unites the two valves.
2. By what means are the animals able to
open these valves ?
* Plate X. figure 4.
QUESTIONS ON BIVALVES. 197
3. What is the meaning of the terms equivalve,
inequivalve, equilateral, inequilateral, and what
is their derivation ?
4. Describe the mollusk inhabiting bivalve
shells ?
5. How is the generic character of bivalve
shells determined ?
6. Name the parts of a bivalve shell, and
describe the situation of each part.
7. What is the generic character of the Mya,
and what are its distinguishing marks ?
8. Describe the manner in which the shell of
the Mya Margaratifera is peculiarly suited to
the situations it occupies.
9. What are pearls, and in what kind of
shells are they found ?
10. What is the generic character of the
Solen, and how is it distinguished ?
11. Describe the habits of the Solen.
12. What is the generic character of the
Tellina, and its distinguishing mark ?
13. What is the generic character of the
Cardium, and its distinguishing marks ?
14. Which species of tne Cardium afford food
to the poorer classes ?
15. What is the general appearance of the
Mactrae ?
16. What is the generic character of the
Donax ?
17. What is the generic character of the
Venus, and its distinguishing mark ?
18. To what use is the Venus Mercenaria
converted ?
198 QUESTIONS ON BIVALVES.
19. What is the generic character of the
Spondylus ?
20. What is the generic character of the
Chama, and its distinguishing mark ?
21. Give an account of the Chama Gigas ?
22. What is the generic character of the Area,
and its distinguishing mark ?
23. What difference occurs in the arrange-
ment of the teeth of the Area ?
24. What is the generic character of the
Ostrea, and its distinguishing mark ?
25. Describe the two great families into
which the Ostrea is divided.
26. Describe the difference in the habits of
the Pecten and the Oyster.
27. Describe the manner of taking and fat-
tening the common oyster.
28. What is the generic character of the
Anomia ?
29. Describe the two families into which the
Anomia is divided.
30. What is the generic character of the
Mytilus ?
31. Describe the habits of the common mus-
cle.
32. Describe the pearl fishery.
33. What is the generic character of the
Pinna ?
34. Why is the Pinna considered as a link
between the univalves and bivalves ?
35. Describe the habits of the animal inha-
biting the Pinna.
199
MULTIVALVES.
This class according to Linnaeus, contains
three genera. The generic character is chiefly
determined by the number of valves and their
position.
Genus.— PHOLAS.*— (Plural. PMades.)
STONE PIERCER.
Generic Character. Shell with two primary
valves gaping at both ends, and several smaller
accessory valves situated upon the hinge and
posterior slope ; hinge recurved, each valve has
a long tooth curved towards.
OBSERVATIONS ON THE SHELL AND ITS
INHABITANT.
The shells of this genus are thin, fragile, and
usually either of a pure or dusky white, adorned
with beautiful minute fret work : the reticulations
in some species are so delicate and fine as to re-
semble lace; in others, they are coarser, and
approaching to small basket work. The
* Plate X. figure 8.
200 MULTIVALVES.
Pholades were ranked by Linnaeus amongst the
multivalves, but by modern conchologists they
are generally placed with the bivalves. The
two principal valves connected by a hinge,
associate them closely to the latter, and the
small testaceous plates around the hinge may
be considered as mere appendages, for they do
not act the part of valves. The Pholas appear
the connecting link between the classes of
bivalves and multivalves. So gradual are the
steps by which the scale of nature proceeds, that
it is often difficult to ascertain precisely the
line which separates its great divisions,
The Pholades are all borers, perforating wood,
clay, limestone, and sometimes burying them-
selves in the sand, forming a retreat in which they
pass their lives. The name marks their peculiar
propensity, being derived from (puXeos, (pholeos)
a hiding place. The largest species, and the finest
specimens are most frequently found in chalk,
which being the softest of calcareous substances,
admits of a more easy and rapid progress to the
animal than the indurated stones in which they
are sometimes discovered. How they effect
their lodgment, is still a subject of doubt and
inquiry. Many have supposed that a continued
rotatory * motion would in time produce such a
cavity as they inhabit, but as it is exactly fitted
to their size, it cannot be easily imagined that
the animal could perform this motion within it.
Another circumstance opposed to this opinion
* Rotatory, like a wheel, from the Latin rota, a wheel.
PHOLAS— STONE PIERCER. 201
is, that the mollusks whose shells are per-
fectly smooth, are capable of producing the
same excavation as those which have a surface
as rough as a file. Many have supposed that
these animals possess some liquid which acts as
a solvent upon the substance they enter. This
appears the more probable, as they are known to
emit a phosphorescent light.
The entrance is the smallest part of the dwell-
ing of the Pholades, and hence it is evident
that they must have penetrated the rock when
young and small, and enlarged their perforations
as they themselves increased in dimensions. The
position of the hole is always oblique to the
horizon : its form that of a truncated cone,
terminated by a rounded cavity. This cavity
receives the body, while the farthest end is
occupied by the proboscis, which is continually
protruded to the orifice to procure the sea water,
upon which it subsists. The proboscis is long,
pliable, and fleshy, terminated by a corneous
substance, which is dentated like a saw at its
extremity. There is an opening between the
valves, through which it is projected, and a case
into which it fits. At the approach of danger,
these mollusks, by means of this instrument
eject water to a considerable height, and its
dentated margin leads us to suppose, that they
also employ it in the work of perforation.
202
PHOLAS Candida*
WHITE STONE PIERCER.
Specific Character. Shell oval, obtuse, nearly
closed at the anterior end, thin, fragile, almost
transparent, striated transversely, and crossed
by finer striae in a radiated form from the um-
bones, a few of the radii at the larger end set
with short spines ; hinge smooth and reflected,
teeth slender and curved ; one valve has a
curved lamina above the tooth ; there is a single
accessory valve ; the colour is yellowish white ;
it is about three quarters of an inch long, and
three inches broad.
These Pholades inhabit marine rocks ; they
are found in great numbers on the Devonshire
coast ; the stone in which they are imbedded is
a cementation of the finest sand and limestone ;
it is very soft when first taken from the bed,
and so absorbent as to afford sufficient moisture
for the purposes of life, and for the peculiar
actions of the mollusk. The animal secretes a
mild phosphorescent solution, which would be
of sufficient power to decompose the rock by
the contact of its gradually increasing bulk.
* Plate X. figure 8.
203
Genus— CHITON.*— (Plural, Ckitones.)
COAT OP MAIL.
Generic Character. Shell multi valve, com-
posed of eight valves, rarely of seven or six ;
form convex oval ; the valves are arranged in an
imbricated manner, the margin of one being in-
cumbent on that of the next ; they are surrounded
and connected by an elastic coriaceous mem-
brane, which allows of the free movement of the
valves, it is either scaly, hairy, or spinous.
OBSERVATIONS ON THE SHELL AND ITS
INHABITANT.
The Chitons are readily distinguished from all
other testaceous mollusca by the form of their
shell, which very much resembles a small vessel
or boat turned upside down, and by the peculiar
arrangement of its moveable valves attached by
a coriaceous membrane. This latter substance
is capable of sufficient expansion and contraction
to admit of considerable play in the valves, so
that the animal can roll up its shell into the
form of a ball, having all the appearance of a
wood-louse. Thus covered by its scales it lies
like a pebble at the bottom of the sea, and so
* Plate X. figure 5.
204 MULT1VALVES.
contrives frequently to escape the vigilance of
its enemies. The mollusks of the Chitons are of
the same form as their shells, the plates of which
are fixed in the mantle ; the gills surround their
bodies ; they breathe only water, and have a
fleshy foot, upon which they creep. Their abode
is in the sea at an inconsiderable depth near the
shore. They fix themselves for a time to rocks
and stones, but they can remove at pleasure.
The situation and formation of the valves resem-
ble the plates which constitute a suit of armour,
or coat of mail ; and to this resemblance the
shell owes its name, which is derived from %ITM,
(chiton) a coat of mail.
CHITON Fascicularis.
TUFTED CHITON.
Specific Character. Shell with eight valves,
apparently smooth, but when viewed through a
glass, found to be rough like shagreen, except
on the elevated dorsal ridge ; the margin is sur-
rounded with tufts of whitish hairs at the junc-
tion of each valve, there are also two tufts in
front, making altogether eighteen. The colour
is brown or dark grey, often mottled ; the length
is rather less than an inch.
The animal of this Chiton adheres to oysters
and other shells, and with them inhabits the
deep : it is also found on stones. It is not un-
common on the coast of Devonshire ; on those
of Barbary it occurs of a much larger size.
LEPAS— BARNACLE. 205
CHITON Squamosus*
SCALY CHITON.
Specific Character. Shell with eight valves,
one half of each valve is striated longitudinally,
and the other half transversely ; the margin
scaly ; the outside is dark brown, more or less
variegated with olive, and the inside is light
bluish green ; the margin is beautifully che-
quered with light green and dark olive scales.
Inhabits the coasts of America.
Genus— LEPAS,f (Plural, Lepades.)
BARNACLE.
Generic Character. Shell multivalve, more
or less of a conical form, either affixed by their
base, or by a peduncle ; valves erect, oval, une-
qual, varying in number, most frequently six.
OBSERVATIONS ON THE SHELL AND ITS
INHABITANT.
This genus consists of two principal divisions ;
the shells contained in the one are sessile, or
affixed at their base, those of the other are
peduncled. •'• «.fy "I
* Plate X. figure 5. t Plate X. figures 6, 7.
206 MULTIVALVES.
Though dissimilar in their appearance, these
shells are united by many points of resemblance ;
they are all more or less of a conical form, com-
posed of several valves, and are parasitical. The
animals inhabiting them are very similar, and
differ much from other mollusks. They have
no head or eyes, the mouth has jaws, with horny
laminae or erect teeth ; but the most singular
part of their structure consists in the numerous
tentacular, curled, articulated arms; these vary
in number, some of the species have as many as
twenty-four. They are arranged in pairs, and
are all inserted together ; the twelve longest are
erect and arched, appearing like curled feathers ;
they are clear and horny ; each joint is furnished
with two rows of hair on the concave side. The
animals make use of these organs to catch their
prey, and are continually extending and con-
tracting them. The twelve smallest are placed
in front, they are more flexible, and more thickly
set with hairs than the others.
The sessile shells * are now formed into a dis-
tinct genus called Balanus: they adhere imme-
diately to marine substances at their base, and
remain immoveably fixed for life ; the form of
the shell is conical, and the valves of which it
is composed, are so strongly cemented as almost
to appear like a single piece. From the con-
struction of the shell, its immoyeable walls, and
its large opening at the apex, the animal would
be in a very exposed and perilous situation,
* Plate X. figure 6.
LEPAS— BARNACLE. 207
had not the compensatory providence of the
Creator been exerted in affording it a safeguard.
This consists of a very efficient operculum, com-
posed of four testaceous pieces, moveable at
pleasure, and articulating with the sides of the
shell, sometimes near the base, sometimes to-
wards the middle. The union of these valves
forms a pointed cone, which completely covers
the opening at the apex, and protects the mol-
lusk, who can open it at pleasure to put out its
arms, and draw in food. The increase in the
height of these shells is clearly indicated on
their lateral valves, whilst at the base are traces
of extension in width ; it is probable that at
each period of growth, the animal disunites its
valves and connects them again, having added
the necessary portion to their size.
The Linnaean name of Lepas is now confined
to the division containing the Peduncled shells.*
The mollusk inhabiting them may be considered
as different from those of the Balanus, because the
tube which supports the shell is in fact a part
of the animal : it is organized, living, and fur-
nished with muscles which give the Lepas the
power of regulating its movements. The shell
is composed of five valves, two on each side,
and one long and narrow on the dorsal ridge ;
these valves are united by a membrane ; the form
of the ^shell is that of a flattened cone ; the base
is sustained by the tubular flexible peduncle, by
which the shell is attached to marine substances.
* Plate X. figure 7.
208 MULTIVALVES.
LEPAS Tintinndbulum*
BELL-SHAPED BARNACLE.
Specific Character. Shell sessile, the valves
irregularly and strongly ribbed longitudinally,
and the interstices delicately striated trans-
versely; the form is sometimes conical, some-
times cylindrical ; the colour is pinkish inclining
to purple ; the diameter, which is sometimes
exceeded by the height, varies from half an inch
to two inches.
This shell is found in the West Indies, and
coasts of Africa, and often on the bottom of
ships arriving from more southern latitudes;
but its claim to be considered as a native of
Britain is very doubtful*
LEPAS Anatifem.^
DUCK BARNACLE.
Specific Character. Shell compressed, some-
what triangular, composed of five valves ;
the two lower ones are large, triangular, and
faintly striated ; the two superior valves long
and tapering downwards to an obtuse point, the
upper part angular on each side, the top roun-
ded ; these valves are also slightly striated ; the
dorsal valve is long, slender and rounded ; the
* Plate X. figure 6. f Plate X. figure 7.
LEPAS— BARNACLE. 209
cartilages that connect the valves and the
peduncle are usually of a reddish orange colour ;
the valves are blueish white ; the length is about
an inch and a half, the breadth of the largest
part is an inch; the peduncle is sometimes a
foot long.
This species is found in all parts of the world,
adhering in great quantities to the bottom of
ships. It attaches itself particularly to wood :
sometimes pieces of timber are thrown on shore
completely covered with it. A most strange
idea formerly prevailed, that the Barnacle goose
was produced from these shells.
QUESTIONS ON THE MULTIVALVE
SHELLS.
1. How is the generic character of Multi-
valve shells determined ?
2. What is the generic character of the Pholas ?
3. Why is the Pholas now generally consi-
dered as a Bivalve shell ?
4. What are the habits of the Pholades ?
5. How is the Phoias supposed to perforate
the different substances it inhabits ?
6. What is the generic character of the
Chiton ?
7. Describe the habits of the Chiton.
P
210 MULTIVALVES.
8. What is the generic character of the Lepas ?
9. Describe the two families into which the
Lepas is divided.
10. Describe the animal which inhabits the
L epas.
USES OF SHELLS AND THEIR
INHABITANTS.
Testaceous bodies are not only to be admired
for their beauty, but valued for their usefulness.
Several of their animals afford a very nutritious
diet. The oyster supplies the table of the rich
with a wholesome delicacy ; in many maritime
situations the poor population are almost entirely
supported by various shell fish, as muscles,
cockles, pectens, solens, &c. The medicinal
qualities of the snail have rendered it a suitable
sustenance for the invalid. Mollusks not only
contribute to supply the wants of man, but they
form the subsistence of other animals ; they are
the prey of various fishes, and are a favourite food
of seafowl, who exert much ingenuity in getting
at them : when they find their beaks insufficient
to pierce a shell, they will ascend with it to
some neighbouring eminence, from whence they
drop it, that it may be crushed against the
rocks. The monkey also regales himself with
shellfish ; at the reflux of the tide, when the
SHELLS AND THEIR ANIMALS. 211
Mollusks for want of water, keep their shells
open, he stations himself on the sea shore, aware
of the danger of inserting his paws between the
valves, he drops in a stone or two, by which
he prevents their closing, and is enabled to
extract his prey with impunity. The shells
also of Testaceous animals are useful in various
ways. In America the greatest quantity of
the lime used for agricultural and architectural
purposes is made of calcined shells. The public
streets of Christianstadt and Santa Cruz are
paved with the Strombus Gigas.
In uncivilized countries the natives not only
delight to deck their persons with shells, but
where the working of iron is still unknown,
they often employ shells as its substitute, and
convert them into agricultural or domestic im-
plements, and also warlike instruments. The
military horn of many of the African tribes is
formed of the Murex Tritonis. The blue and
white belts of the Indians of North America,
used as symbols of peace and amity, in oppo-
sition to the war hatchet, is made from the Venus
Mercenaria ; and the gorget of the chieftain's
dress, is constructed of the Mytilus Margarati-
ferus. Among the Friendly Isles the permission
to wear the Cyprsea Aurantia or Orange Cowry
marks the highest rank of the country. The
Cypraea Moneta or Money Cowry is the current
money of many nations of India and Africa,
and the liberty of a man is often bartered for*
a certain weight of these shells. In Grecian
p 2
212 SHELLS AND THEIR ANIMALS.
History we read that the suffrages of the
Athenians were on certain occasions marked
upon a shell. Pearls, the effect of disease in
certain Mollusca, form a portion of the revenue
of many kingdoms, and are among the most
costly ornaments of the noble and the wealthy.
In former times the dye extracted from the Pur-
pura was a most valuable article of commerce,
but it has now been superseded by that which
the Cochineal furnishes in so much greater
abundance.
213
A LIST OF THE GENERA OF SHELLS
AS ARRANGED BY LINNAEUS.
MULTIVALVES.
Chiton.
Lepas.
Pholas.
Plural.
Chitones.
Lepades.
Pholades.
BIVALVES.
Mya.
Solen.
Tellina.
Cardium.
Mactra.
Donax.
Venus.
Spondylus.
Chama.
Area.
Ostrea.
Anomia.
My til us.
Pinna.
Myae.
Solenes.
Tellinae.
Cardia.
Mactrae.
Donaces.
Veneres.
Spondyli.
Chamae.
Arcae.
Ostreae.
Anomiae.
Mytili.
Pinnae.
214
UNIVALVES.
Plural
Argonauta.
Nautilus.
Argonautae.
Nautili.
Conus.
Coni.
Cypraea.
Bulla.
Cypraeae.
Bull-*.
Voliita.
Volutae.
Buccinum.
Buccina.
Strombus.
Strombi.
Murex.
Murices.
Trochus.
Trochi.
Turbo.
Turbines.
Helix.
Helices.
Nerita.
Neritae.
Haliotis.
Haliotides.
Patella.
Patellae.
Dentalium.
Dentalia.
Serpula.
Teredo.
Serpiilae.
Teredines.
Sabella.
Sabellse.
TABLE OF THE
LINN^AN GENERA OF SHELLS,
WITH LAMMARCK'S DIVISION OF THESE GENERA.
LAM.
LIN. LAM.
Chiton, l
Chitonellus.
VII. Cardium. -{ Cardium.9
rTubinella
f Lutraria.
Coronula,
nearly all.
Balanus.2
Mactra.'O
Acasta.
VIII. Mactra. -( Crassatella.
Creusia.
part.
Pyrgoma,
, - - . • i
Amphidesma.
Anatifa.3
part. ,
Pollicipes.
Cineras.
(Petricola.
^Otion.
part.
f Pholas.4
[ Gastrochsena.
Venerupis.
part.
Donax.n
Panopsea.
Capsa.
Glycimeris.
Mya.s
r Petricola.
Anatina.
part.
Lutraria.
Venerupis.
part.
part.
Amphidesma.
Sanguinolaria.
fart.
part.
Corbula.
Corbis.
Unio.
Hyria.
Ivulsella.
X. Venus.
Lucina. part
Donax. part.
Crassina.
, Solen.6
I Anatina. part.
i Sanguinolaria.
LHiatella.
Cyrena. part*
Galathea.
Cyprina.
Cytherea.
Venus.12
'Mya. part.
^
Amphidesma.
part.
XI. Spondylus. J s^onxMus3"
Pandora.
'
Psammobia.
fCardita.
* Psammotxa.
Cypricardia.
Tellina.7
Lucina.8
VTI nv.«« Isocardia.15
XII. Chama. J chama
Cyclas.
1 Tridacna.
^Cyrena.
^Hippopus.16
1 Plate 10. fig. 5.
5 Plate 10. fig. 7. 8.
9 Plate 8. fig. 1, 2.
13 Plate 8. fig. 9.
2 Plate 10. fig. 6. 3 Plate 10. fig. 7, 4 Plate 10. fig. 8.
6 Plate 7. fi-s 3. 4. 7 Plate 7. fig. 6, 8.9- 8 Plate 7. fig. 7-
10 Plate 8. fig. 3, 4, 9. 11 Plate 8. fig. 5, 6. 12 Plate 8. fig. 7.
14 Plate 8. fig 10. 15 Plate 9. fig. 3. 16 Plate 9. fig. 2 .
216
LINN^EAN GENERA OF SHELLS.
LIN.
LAM. LIN LAM.
Bull sea.
fNucula.
Acera.
XIII. Area.
I Pectunculus. 1
] Area. 2
Bulla. «3
Bulimus.
1 Cucullaea.
XXII. Bulla.
Achatina.
part.
Physa.14 part.
: « .I'!-;
Ovula.'S
(
' Cucullsea.
.Terebellam.
f Auricula.
XIV. Ostrea.
port*
Perna.
MaUeus.3
- Pedum
Lima
1 Ancilla.
Tornatella.
Turbinella.
j Cancellaria.
Pecten.4
Gryphaea.
XXIII. Voluta.
Columbella.
Mitra. 16
Voluta.
• '-'Strea.
Marginella.
Volvaria.
fPlacuna.
Achatina.
1 Anomia.5
^Oliva.i7 -9
XV. Anomia.
j Crania.
1 Orbicula.
'Concholepas.
Achatina
j Terebratula. 6
port.
V-Hyalaea.
Phasianella.
Pleurotoma.
iSaxicava.
Turbinella.
Anadonta.
part.
Modiola.
Cancellaria.
XVI. Mytilus.
Mytilus.7
Avicula.
part
Pyrula. part.
Melleagrina.8
XXIV. Buccinum. •
Mnrex. part
Ostrea. some*
Triton.
Cassidaria.
XVII. Pinna,
-{ Pinna.
Cassis.i8
i
Purpura.
Monoceroe.
( Argonauta. 9
XVIII. Argonauta. j Carinaria.
Harpa.19
Dolium. V
Buccinum.
Eburna.
XIX. Nautilus.
/Orthocera.
/ Nodosaria.
1 Spirula.
1 Cristellaria.
iNautilus.io
^Terebra.*1
/• Pirena.
Cerithium.
part,
Pleurotoma.
part.
XXV. Strombus. .
Rostellaria.22
XX. Conus.
•{ Conus.n
Pterocera.
Strombus.
Cassadaria.
XXI. Cypraea.
-{ Cypraea.i2
part-
„ Purpura.
1 Plate 9. fig. 5.
2 Plate fie. 6. 3 Plate 9. fig 8. 4 Plate 9. fig. 7,
5 Plate 10. fig. 1.
9 Plate 6. fig. 5.
6 Plate 9. fig. 9. 7 Plate 10. fig. 2. 8 Plate 10. fig. 3.
10 Plate6.fig. 4. 11 Plate 2. fig. 1. 12 Plate2.fig. a, 4, 5.
13 Plate 2. fig. 6.
14 Plate 2. fig. 9. 15 Plate 2. fig. 8 16 Plate 2. ft. ll.
17 Plate2. fig. 10.
18 Plate 3. fig. 3, 19 Plate 3. fig. 2. 20 Plate 3. fig. 1.
21 PlateS. fig. 4. 22 Plate3.fig.6.
LIN.
XXVI. Murex.
XXVII. Trochus.
XXVIII. Turbo.
XXIX. Helix.
1 Plate 3- fig. 2.
5 Plate 6. fig.5.
9 Plate 4. fig. 3.
13 Plate 5. fig. 8.
17 Pla
INN^EAN GENERA OF SHELLS. 217
LAM.
LIN. LAM.
rCerithina.
Planorbis. s
Pleurotoma.
Lymnsea.9
Turbinella.
Melania.
part.
Melanopsis.
1 Fasciolaria.
Paludina. part.
| Fusus.
Valvata.
J Pyrula.
Ampullaria.
Struthiolaria.
Natica*
Ranella.l <
lanthina.
Murex.2
Sigaretus.
Triton. 3
Prienula.
Purpura.
r Navicella.
part.
XXX. Nerita. \ Nerita"*'
Pyramidella. 4
I Natica.
Solarium. 5
Rotella.
Trochus.
Monodonta.
( Stomatia.
XXXI. Haliotis. \ Haliotis.i*
part.
Cerithrum.
part.
r Lingula.
'Pupa.
Clausilia.
Auricula.
part.
Cyclostoma.
Planorbis.
part.
Paludina.
Scalaria.6
Delphinula.
Patella.
Umbrella.
Parmophorus.
Emarginula.
XXXII. PateUa. \ FissureUa.'3
Pileopsis.'4
Calyptrsea.i5
Crepidula. ,
Ancylus.
Lstomatella.
Trochus. part.
Monodonta.
part.
XXXIII. Dentalium. Dentalium.ic
Turbo.
Turritella.
ISiliquaria.
'Helix. 7
Spirorbis.
Carocolla.
Serpula.
Anostoma.
Helicina.
IrS^Sum i7
part.
Septaria.
Pupa. some.
part.
Bulimus.
(^Vermetus. is
part.
Succinea.
Auricula.
part.
Cyclostoma.
part.
fFistulana.
XXXV. Teredo. J Septaria. part
(^Teredo.
Plate 4. fig. 1. 3 Plate 4. fig. 3. 4 Plate 4. fig. 6.
, Plate 4. fig. 78. 7 Plate 4. fig. 1. 8 Plate 4. fig 2.
Plate 5! fig.5. ' 11 Plate5. fig. 4. 12 Plate 5. fig. 6.
Plate 6. fif. 1. 15 Plate 5. fig. 4. 16 Plate 6. fig. 6.
218
EXPLANATION OF TJ3RMS.
Acephala. Without a head from the Greek
K€<paXv) (cephale) a head.
Apex. In univalve shells, the top of the spire.
Apices. The plural of apex. In bivalve shells,
the points over the hinge : called also
the Beaks. ;
Aperture. The entrance or opening of the shell.
Auricula. Small earlike appendages placed at
the sides of the hinge of some bivalve
shells : the diminutive of auris, an ear.
Area, or Anterior slope. The side of the beaks
where the ligament is situated.
Areola, or Posterior slope. The side of the
beaks opposite to that where the liga-
ment is placed.
Articulated. Having joints ; from articul us, a
joint.
Annulated. Marked with rings ; from annul us.
a ring.
Alatce. Winged ; from ala, a wing.
Adductor Muscle. The muscle that closes the
valves ; from adduce, I bring together.
Base. In univalve shells, the extremity oppo-
EXPLANATION OF TERMS. 219
site to the apex. In bivalve shells that
part of the margin which is opposite to
the beaks.
Bivalve. A shell with two valves; from bis,
twice, and valve.
Bifid. Cleft in two ; from bis, twice, and fid i,
I have cleft.
Bifurcated. Having a fork of two teeth ; from
bis, twice, and furc a, a fork.
Branchiae. Gills; from the Greek /-fyayxta,
(branchia) the gills of fish.
Cardo or Hinge. In bivalves, that part of the
circumference where the valves cohere.
Carinate. Furnished with a keel-like elevated
ridge; from carina, a keel.
Columella. The pillar round which the whorls
form their spiral circuit; from columella,
a little column. ;*
Convoluted. Rolling regularly over each other ;
from con, together ; and volut us, rolled.
Cephalopodes. Having feet on the head ; from
the Greek /ce^aX^, (cephale) a head, and
7ro&€$, (podes) feet.
Cephala. Having a head ; from the Greek
K€<pahy (cephale) a head.
Corneous. Horny ; from cornu, a horn.
Crenated. Notched ; from cren a, the notch of
an arrow.
Coriaceous. Like leather ; from cori um, skin,
leather.
Callosity. Hardness of skin or flesh ; from
call us, which has the same signification.
220 EXPLANATION OF TERMS.
Ciliated. Furnished with a fringe like eye-
lashes ; from cilia, an eyelash.
Cordate. Heart-shaped ; from the Latin (cor)
a heart.
Contracted. The mouth is called contracted,
when the lips are not separated by any
channel or sinus ; it then holds liquids
though filled up to the brim.
Congener. One of the same genus ; from con,
together and genus, a kind.
Coronated. Crowned or girt towards the apex.
Cancellated. Crossed like the bars of a latticed
window ; from cancelli, lattice.
Complicated. Folded together; from con, with,
together, and plicare, to fold.
Digitations or Claws. Finger-like lobes ; from
digitws, a finger.
Dextral. Righthanded, turning round the pil-
lar from left to right, the usual course of
the whorls ; from dextra, the right hand.
Dorsal. Belonging to the back ; from dorszm,
the back.
Deciduous. Falling, not lasting ; from decido,
I fall.
Dentated. Toothed ; from dens, a tooth.
Diaphanous. Capable of transmitting light,
transparent; from the Greek &a (dia)
through, and paivu (phaino) I appear.
Decorticated. Having the bark or outer skin
taken off ; from de, off, and cortex, bark.
Dissepiment. A division between two chambers
in a shell ; from sepes, a hedge, and dis,
EXPLANATION OF TERMS. 221
a prefex, signifying division.
Decussated. Crossed like an X ; from decussis,
the mark X (ten).
Disk. The convex part of the valves between
the urn bones and the margin, applied also
to any extended or rounded surface ; as in
Haliotis, from the Latin discus, a dish
or platter.
Effuse. Having the lips separated by a sinus
or gutter, so that if the shell were filled
with water, it would flow out at the sinus
before it reached the margin ; from fus us,
poured out.
Epidermis. The membranaceous covering of
some species of shells ; from the Greek
em (epi) upon, and $ep/xa (derma) a skin.
Eroded. Gnawed out, from the Latin e, out,
and rod ere, to gnaw.
Entire. The mouth is said to be entire, when
the lips are not separated by a canal.
Equivalve. Having equal valves ; from equ us
equal, and valve.
Equilateral. Having both sides equal ; from
equ us, equal, and latera, sides.
Emarginated. Notched, or having the margin
excavated by a sinus.
Ferruginous. The colour of rust or iron-mould ;
from ferrugo, iron rust.
Flexuous. Winding full of turns and meanders.
Fusiform. Shaped like a spindle; swollen in
the middle, and tapering to each end;
from fusis, a spindle.
222 EXPLANATION OF TERMS.
Fluviatile. Belonging to fresh water; from
fluviws, a river.
Globose, Globular. Approaching the form of a
globe.
Genus. A separate family, distinguished from
all others by certain permanent marks,
called generic characters ; from gen us, a
kind.
Gibbous. Convex, swelling out, from gibbus,
a swelling, a hunch on the back.
Gaping. The valves so partially closing, that
the margins do not touch at every part of
the circumference.
Imbricated. Lying one over another like the
tiles of a house ; from imbrex, a tile.
Iridescent. Displaying the varied colours of
the rainbow ; from iridescere, to shine
like a rainbow, in Latin iris.
Insterstice. Space between one part and another.
Inequivalve. Having unequal valves ; from in,
not, equ us, equal, and valve.
Inequilateral. Having sides not uniform ;
from in, not, equ us, equal, and latera,
sides.
Involuted. Rolled inwards ; from involut us,
rolled up in.
Littoral. Belonging to the shore ; from litt us,
a shore.
Lateral. At the sides ; from later a, sides.
Longitudinal. In the direction of the length of
a shell; ( i. e. ) from the apex to the
base.
EXPLANATION OF TERMS. 223
Laminated. Having thin layers or scales called
laminae.
Linear. Having the character of a line ; ex-
tremely narrow in proportion to its
breadth, and of nearly equal diameter
throughout.
Length. In Bivalves, the dimension extending
from the hinge to the opposite margin ;
in Univalves, that from the apex to the
base.
Ligament. A cartilage which connects the
valves ; from lig are, to bind.
Lanceolate. Shaped like the head of a lance.
Lips. The margins of the mouth of a univalve
shell. The columellar lip is the margin
nearest the columella. The outer Up is
the outer margin of the aperture.
Locomotion. The power of moving voluntarily
from place to place ; from loc us, place,
and motion.
Lubricated. Slippery ; having a very smooth
surface ; from lubric us, slippery.
Multivalve. Having several valves, from
mult us, many.
Mollusca. The animals inhabiting shells ; the
name is derived from mollis, soft. They
are divided into two classes : those which
have a head called Mollusca Cephala,
from the Greek ice^aX^, (cephale) a head ;
and those without a head Mollusca ace-
phala, from the Greek a (a) without, and
224 EXPLANATION OF TERMS.
Muricated. Having little pointed knobs ; from
murex, the sharp point of a rock.
Marine. Belonging to the sea ; from mare, the
sea.
Multilocular. Having several chambers, from
mult us many, and locul um, a little
chamber.
Operculum or Lid. A plate or door, with which
some species close the aperture of their
shells, from oper iort I cover.
Orbicular. Quite round, or circular.
Parallel. Running in the same direction as
another thing, being always at the same
distance from it; from the Greek napa
(para) by the side of, and aXT^A wv (alle-
lon) each other.
Pellucid. So clear that the light is seen through ;
from per, through, and lua?, light.
Pervious. Easily passed through ; from per,
through, and via a way.
Plicated. Folded or plaited ; from plica, a
fold.
Punctured. Pricked or marked with small
dots ; from punct um, a point or dot.
Patulous, lying open or spreading ; from pat er€t
to lye open.
Quincunx. Disposed alternately as in rows of
spots, when the spots of each row are
opposite to the space between two spots
of the next row ; from quin^we, five, and
unx, ounce, as the weight representing
five ounces was stamped thus :•:
EXPLANATION OF TERMS. 225
Rotatory. Like a wheel; from rota, awheel.
Rostrated. Having a beak from rostrwra, a
beak.
Refuse. Having the lower whorls of the spire
pressed into the body whorl, from re-
back, and tusws, beaten.
Reversed. Applied to spiral shells, whose volu-
tions turn in the contrary direction to
the generality of shells, If when a shell is
placed on its base, with the front facing
the person looking at it, the aperture is
on the right side of the pillar, the shell is
said to be regular or dextral, if the aper-
ture is on the left side of the pillar, it is
said to be reversed or sinistral.
Retractile. Capable of being drawn back ; from
re, back, and tract us, drawn.
Reticulated. Crossed like net work ; from reti-
culww, a small net.
Revolute. Rolled back ; from re, back, and
volutws, rolled.
Rugose. Rough or wrinkled ; from ruga, a
wrinkle.
Rufous. Of a reddish colour.
Spire. The upper whorls collectively , from
the Greek a-ireip (speir), convolutions
gradually increasing in diameter.
Suture. The circular line of the spire, where
one volution meets another ; from sutura,
a seam.
Species. The subdivision of a genus, and dis-
tinguished from all others of the genus
Q
226 EXPLANATION OF TERMS.
by permanent marks called specific
characters.
Striated. Marked with fine striae, or lines,
either hollow or raised ; from stria, a
stripe.
Sinus. A gutter, or curvature ; from sinws, a
curved line.
Sinuous. Having a curvature.
Subulate. Tapering, or pointed ; from subula,
a pointed tool.
Sagittate. Arrow-like ; from sagitta, an arrow.
Siphon. A pipe through which liquids are
conveyed.
Sub. In composition means almost, or ap-
proaching to.
Setaceous. Bristle shaped ; from seta, a bristle.
Semi. Half.
Sinistral. On the left hand ; from sinistra, the
left hand.
Sides. The right side of a univalve is that
opposite the right hand of the person
looking at it, when the shell is placed on
its base with the aperture in front : the
left side is that opposite the left hand,
the shell being in the same position.
Terrestrial. Belonging to the earth ; from
terra, earth.
Testaceous. Composed of the materials which
form shells ; from the Latin testa, a
shell.
Tentacula. The feelers of the mollusca ; from
the Latin ten to, I try.
EXPLANATION OF TERMS. 227
Turbinate. The body swelling, and spire com-
paratively small ; from the Latin tur-
bin is, of a whirlwind.
Turreted. The whorls gradually decreasing to
a fine point ; the length of turreted shells
greatly exceeds their breadth.
Turgid. Swollen, puffed up.
Teeth. The pointed protuberances at the hinge
of bivalve shells; the cardinal or central
teeth are those situated on the hinge ;
the Lateral teeth are those at the sides
of the hinge, and are often remote.
Tuberculated. Covered with tubercles, or small
protuberances.
Tortuous. Twisted; from the Latin tort MS,
twisted.
Transverse. Placed across, or crossways.
Truncated. Cut short or abruptly off at the
end.
Umbones, or Bosses. The swelling parts of
bivalve shells near the beaks ; from umbo,
the boss of a shield. The highest points
of these are considered the summits.
Umbilicus. A small hollow at the base of the
columella, visible underneath.
Undulating. Wave-like ; from undula, a little
wave.
Univalve. A shell composed of one valve ; from
unws, one, and valve.
Volution or Whorls. The distinct turns of
the spire.
Varices. Longitudinal gibbous sutures formed
Q 2
228 EXPLANATION OF TERMS.
in the growth of the shell at certain
distances on the whorl ; from varix, a
swollen vein.
Vermiform. Resembling a worm ; from the
Latin vermes, a worm ; and forma, a
form.
Ventricose. Inflated. Swelled in the middle.
THE END.
EXPLANATION OF THE PLATES.
PLATE I.
a.
b.
c.
Spire.
Body whorl.
Beak.
r.
s.
Area or Anterior
slope.
Areola or Posterior
d.
e.
Base.
Canal.
t.
slope.
Beaks.
9-
h.
i.
Aperture.
Outer lip.
Columellar lip.
Whorls.
u.
V.
w.
X.
Hinge.
Ligament.
Disk.
Umbo.
k.
I.
m.
Suture.
Apex.
Back.
y-
z.
a.*
Base.
Length.
Breadth.
n.
Varices.
b*
Auricles.
0.
Columella.
c*
Left valve.
P-
Dissepiments.
Umbilicus.
d*
e*
Right valve.
Valves.
PLATE II.
FIG.
1. Conus marmoreus.
2. Cyprsea arabica .
3. The same^ young.
4. Cypraea moneta
5. Cypraea europcea .
6. Bulla lignaria .
7. Gizzard of Ditto.
8. Bulla volva.1 . .
9. Bulla fontinalis.2 .
10. Voluta o&va.3 . .
11. Voluta episcopalis.*
Marble Cone.
Nutmeg Cowry.
Money Cowry.
Nun Cowry.
Wood Dipper.
Weaver's Shuttle.
Stream Dipper.
Olive Volute.
Bishop's Mitre.
1 Ovula Volva of Lamarck.
2 Physa Fontinalis Ditto.
3 Oliva Ditto.
4 Mitra Episcopalis Ditto.
PLATE III.
FIG.
1. Buccinum dolium l
2. Buccinum harpa 2
3. Buccinum flammeum 3
4. Buccinum subulatum*
5. S trombus pes pelicani 5
(i. The same, young \ .
Spotted Tun.
Harp Shell.
Triangular Helmet.
Tiger Spire.
Pelican's Foot.
1 Dolium Maculatum t)f Lamarck.
2 Harpa Ventricosa ditto,
s Cassis Flammea ditto.
4 Terebra Macidata ditto.
» Rostellaria Pes Pelicani ditto.
PLATE IV.
1. Murex ramosus . .
2. Murex rana1 . . .
3. Murex maculosus 2
4. Trochus zizyphinus .
5. Trochus perspectivus 3
6. Trochus dolabratus 4 .
7. Turbo scalaris5
8. Turbo clathrus6 .
Branched Murex.
Frog Murex.
Spotted Murex.
Livid Top Shell.
Staircase Shell.
Zebra Shell.
Wentle Trap.
False Wentle Trap.
1 Ranella Crumersia of Lamarck.
2 Triton Maculosus ditto.
3 Solarium Perspectwum, ditto.
4 Pyramidella Dolabrata ditto.
f> Scalaria Pretiosa ditto.
6 Scalaria Communis ditto.
PLATE V.
FIG
1.
2.
Helix pomatia .
Helix cornea1
. Eatable Snail.
. Horn Snail.
3.
4.
5.
Helix stagnalis 2
Nerita peloronta
Nerita corona3 .
. Lake Snail.
. Bleeding Tooth.
Coronated Nerite.
6.
Haliotis tuberculata
Common Sea-ear.
7.
8.
Patella equestris* .
Patella nodosa 5
{Cup and Saucer
Limpet.
Knotted Limpet.
i Planorbis corneous
2 Hymnsea stagnalis
3 Neritina corona
4 Calyptraea equqstris
5 Fissurella nodosa
of Lamarck,
ditto,
ditto,
ditto,
ditto.
r
/ / /
.*.
PLATE VI.
FIG.
1. Patella ungarica1
2. Serpula lumbricalis z
3. Serpula aquaria3
4. Nautilus Pompilius
5. Argonauta argo .
6. Dentalium entails
Hungarian Bonnet.
Cork Screw Shell.
Watering Pot.
7 Large Chambered
) Nautilus.
Paper Nautilus.
Dog's Tooth.
1 Pileopsis Ungarica by Lamarck.
3 Vermetus Lumbricalis by ditto
3 Aspergellum Javanum by ditto
R
PLATE VII.
FIG.
1. Hinge of Mya.
2. Mya truncata . . Truncated Gaper.
3. Hinge of Solen.
4. Solen siliqua . . Pod Razor Shell.
5. Solen radiatus . . Radiated Solen.
6. Hinge of Tellina.
7. Tellina carnaria l . Rosy Tellen.
8. Tellina lingua fells . Cat's Tongue Tellen.
9. Tellina Madaqasca- 1 ».- , ^ „
riensis. } Madagascar Tellen.
1 Lucnia Carnaria of Lamarck.
YIT
PLATE VIII.
FiG.
1. Hinge of Cardium.
2. Cardium edule
3. Hinge of Mactra.
•
4. Mactra stultorum.
5. Hinge of Donax.
6. Donax denticulata .
7. Hinge of Venus.
8. Venus dysera . ; . •
9* Spondylus gcedaropus
10. Spondylus plicatula l
Common Cockle^
( Simpleton's
( Kneading-trough.
, Toothed Donax.
Ribbed Venus.
Thorny Oyster.
Cat's Paw.
1 Plicatula ramosa of Lamarck.
PLATE IX.
FIG.
1. Hinge of Ohama.
2. Chama hippopus l
3. Chama cor2 . .
4. Hinge of Area.
5. Area undata 3 .
6. Area Noce ..
7. Ostrea violacea 4
8. Ostrea malleus6 .
Bear's Paw Clam.
Heart Clam.
Lettered Ark.
Noah's Ark.
Violet Scallop.
HammerOyster.
1 Hippopus maculatus of Lamarck
2 Isocardia cor ditto.
3 Pectunculus undulatus ditto.
4 Pecten violacea ditto.
5 Malleus Vulgaris ditto.
6 Terebratula psittacea ditto.
PLATE X.
PIG.
1. Anomia ephippium
2. My til us edulis
3. Mytilus margaritiferus }
4. Pinna pectinata . . .
5^ Chiton squamosus
6. Lepas tintinnabulum ~.
7. Lepas anatifera z
8. Pholas Candida . . .
Wrinkled Anomia.
Common- Muscle.
Peajl-bearing
( Muscle.
Spiny Sea Wing. •
Scaly Chiton.
Bell-shaped
Barnacle.
Duck Barnacle,
j White Stone-
( piercer.
1 Meleagrina tnargaratifera of Lamarck
2 Balanus tmtimmbulum ditto.
3 Anatifa I avis ditto.
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